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Palindrome Partitioning

Last Updated : 08 Mar, 2024
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Given a string str, a partitioning of the string is a palindrome partitioning if every sub-string of the partition is a palindrome, the task is to find the minimum number of cuts needed for palindrome partitioning of the given string.

Palindrome Partition

Examples :  

Input: str = “geek” 
Output:
Explanation: We need to make minimum 2 cuts, i.e., “g ee k”

Input: str = “aaaa” 
Output: 0 
Explanation: The string is already a palindrome.

Input: str = “abcde” 
Output: 4

Input: str = “abbac” 
Output:

Recommended Practice

Recursive Approach for Palindrome Partitioning:

This is the naive approach to solving the Palindrome Partitioning problem. In this approach, we will try to apply all possible partitions and at the end return the correct combination of partitions.

This approach is similar to that of Matrix Chain Multiplication problem.

In this approach, we recursively evaluate the following conditions:

  • If the current string is a palindrome, then we simply return true, as Palindrome Partitioning is possible.
  • Else, like the Matrix Chain Multiplication problem,
    • we try making cuts at all possible places,
    • recursively calculate the cost for each cut
    • return the minimum value.

Below is the implementation of the above approach.

C++




// C++ Code for Palindrome Partitioning
// Problem
 
#include <bits/stdc++.h>
using namespace std;
 
// Function to Check if a substring is a palindrome
bool isPalindrome(string String, int i, int j)
{
    while (i < j) {
        if (String[i] != String[j])
            return false;
        i++;
        j--;
    }
    return true;
}
 
// Function to find the minimum number of cuts needed for
// palindrome partitioning
int minPalPartion(string String, int i, int j)
{
    // Base case: If the substring is empty or a palindrome,
    // no cuts needed
    if (i >= j || isPalindrome(String, i, j))
        return 0;
 
    int ans = INT_MAX, count;
 
    // Iterate through all possible partitions and find the
    // minimum cuts needed
    for (int k = i; k < j; k++) {
        count = minPalPartion(String, i, k)
                + minPalPartion(String, k + 1, j) + 1;
        ans = min(ans, count);
    }
 
    return ans;
}
 
// Driver code
int main()
{
    string str = "ababbbabbababa";
 
    // Find the minimum cuts needed for palindrome
    // partitioning and display the result
    cout
        << "Min cuts needed for Palindrome Partitioning is "
        << minPalPartion(str, 0, str.length() - 1) << endl;
 
    return 0;
}


Java




//
public class PalindromePartitioning {
 
    // Function to Check if a substring is a palindrome
    static boolean isPalindrome(String str, int i, int j)
    {
        while (i < j) {
            if (str.charAt(i) != str.charAt(j))
                return false;
            i++;
            j--;
        }
        return true;
    }
 
    // Function to find the minimum number of cuts needed
    // for palindrome partitioning
    static int minPalPartition(String str, int i, int j)
    {
        // Base case: If the substring is empty or a
        // palindrome, no cuts needed
        if (i >= j || isPalindrome(str, i, j))
            return 0;
 
        int minCuts = Integer.MAX_VALUE;
 
        // Iterate through all possible partitions and find
        // the minimum cuts needed
        for (int k = i; k < j; k++) {
            int cuts = minPalPartition(str, i, k)
                       + minPalPartition(str, k + 1, j) + 1;
            minCuts = Math.min(minCuts, cuts);
        }
 
        return minCuts;
    }
 
    // Driver code
    public static void main(String[] args)
    {
        String str = "ababbbabbababa";
 
        // Find the minimum cuts needed for palindrome
        // partitioning and display the result
        System.out.println(
            "Min cuts needed for Palindrome Partitioning is "
            + minPalPartition(str, 0, str.length() - 1));
    }
}


C#




using System;
 
// Function to Check if a substring is a palindrome
public class PalindromePartitioning {
 
    // Function to Check if a substring is a palindrome
    static bool IsPalindrome(string str, int i, int j)
    {
        while (i < j) {
            if (str[i] != str[j])
                return false;
            i++;
            j--;
        }
        return true;
    }
 
    // Function to find the minimum number of cuts needed
    // for palindrome partitioning
    static int MinPalPartition(string str, int i, int j)
    {
        // Base case: If the substring is empty or a
        // palindrome, no cuts needed
        if (i >= j || IsPalindrome(str, i, j))
            return 0;
 
        int minCuts = int.MaxValue;
 
        // Iterate through all possible partitions and find
        // the minimum cuts needed
        for (int k = i; k < j; k++) {
            int cuts = MinPalPartition(str, i, k)
                       + MinPalPartition(str, k + 1, j) + 1;
            minCuts = Math.Min(minCuts, cuts);
        }
 
        return minCuts;
    }
 
    // Driver code
    public static void Main(string[] args)
    {
        string str = "ababbbabbababa";
 
        // Find the minimum cuts needed for palindrome
        // partitioning and display the result
        Console.WriteLine(
            "Min cuts needed for Palindrome Partitioning is "
            + MinPalPartition(str, 0, str.Length - 1));
    }
}


Javascript




<script>
 
// Javascript code for Palindrome
// Partitioning Problem
 
// Function to Check if a substring is a palindrome
function isPalindrome(String, i, j)
{
    while (i < j)
    {
        if (String[i] != String[j])
            return false;
             
        i++;
        j--;
    }
    return true;
}
 
// Function to find the minimum number of cuts needed
// for palindrome partitioning
function minPalPartion(String, i, j)
{
    // Base case: If the substring is empty or a palindrome,
    // no cuts needed
    if (i >= j || isPalindrome(String, i, j))
        return 0;
         
    let ans = Number.MAX_VALUE, count;
     
     
    // Iterate through all possible partitions and find the
    // minimum cuts needed
    for(let k = i; k < j; k++)
    {
        count = minPalPartion(String, i, k) +
        minPalPartion(String, k + 1, j) + 1;
        ans = Math.min(ans, count);
    }
    return ans;
}
 
// Driver code
let str = "ababbbabbababa";
 
// Find the minimum cuts needed for palindrome
// partitioning and display the result
document.write("Min cuts needed for " +
               "Palindrome Partitioning is " +
               minPalPartion(str, 0, str.length - 1));
 
</script>


Python3




# Function to Check if a substring is a palindrome
def is_palindrome(string, i, j):
 
    while i < j:
        if string[i] != string[j]:
            return False
        i += 1
        j -= 1
    return True
 
#  Function to find the minimum number of cuts needed for palindrome partitioning
 
 
def min_pal_partition(string, i, j):
 
    # Base case: If the substring is empty or a palindrome, no cuts needed
    if i >= j or is_palindrome(string, i, j):
        return 0
 
    ans = float('inf')
 
    # Iterate through all possible partitions and find the minimum cuts needed
    for k in range(i, j):
        count = min_pal_partition(string, i, k) + \
            min_pal_partition(string, k + 1, j) + 1
        ans = min(ans, count)
 
    return ans
 
 
# Driver code
if __name__ == "__main__":
    str = "ababbbabbababa"
 
    # Find the minimum cuts needed for palindrome partitioning and display the result
    print("Min cuts needed for Palindrome Partitioning is",
          min_pal_partition(str, 0, len(str) - 1))


Output

Min cuts needed for Palindrome Partitioning is 3

Time Complexity: O(2n)
Auxiliary Space: O(n)

Optimising Overlapping Sub-problems in Recursive Approach for Palindrome Partitioning in (O(n3)):

The above recursive approach has overlapping subproblems, leading to redundant computations thereby resulting in exponential time complexity. This redundant computation can be solved by using Dynamic programming approach.

Here, we can use two 2D array C[][] and P[][], for storing the computed result.

  • C[i][j] stores the minimum number of cuts needed for the substring str[i..j],
  • while P[i][j] stores whether the substring str[i..j] is a palindrome or not.
  • It starts with smaller substrings and gradually builds up to the entire string.

Below is the implementation of the above approach:

C++




// Dynamic Programming Solution for
// Palindrome Partitioning Problem
#include <bits/stdc++.h>
using namespace std;
 
// Returns the minimum number of cuts
// needed to partition a string
// such that every part is a palindrome
int minPalPartion(string str)
{
    // Get the length of the string
    int n = str.length();
 
    // Create two arrays to build the solution in bottom up
    // manner
 
    // C[i][j] = Minimum number of cuts needed for
    // palindrome partitioning of substring str[i..j]
    int C[n][n];
 
    // P[i][j] = true if substring str[i..j] is palindrome,
    // else false
    bool P[n][n];
 
    // Note that C[i][j] is 0 if P[i][j] is true
 
    // Every substring of length 1 is a palindrome
    for (int i = 0; i < n; i++) {
        P[i][i] = true;
        C[i][i] = 0;
    }
 
    // L is substring length. Build the
    // solution in bottom up manner by
    // considering all substrings of
    // length starting from 2 to n.
    // The loop structure is same as Matrix
    // Chain Multiplication problem
    for (int L = 2; L <= n; L++) {
 
        // For substring of length L, set
        // different possible starting indexes
        for (int i = 0; i < n - L + 1; i++) {
            int j = i + L - 1; // Set ending index
 
            // If L is 2, then we just need to
            // compare two characters. Else
            // need to check two corner characters
            // and value of P[i+1][j-1]
            if (L == 2)
                P[i][j] = (str[i] == str[j]);
            else
                P[i][j]
                    = (str[i] == str[j]) && P[i + 1][j - 1];
 
            // IF str[i..j] is palindrome, then C[i][j] is 0
            if (P[i][j] == true)
                C[i][j] = 0;
            else {
 
                // Make a cut at every possible
                // location starting from i to j,
                // and get the minimum cost cut.
                C[i][j] = INT_MAX;
                for (int k = i; k <= j - 1; k++)
                    C[i][j] = min(
                        C[i][j], C[i][k] + C[k + 1][j] + 1);
            }
        }
    }
 
    // Return the min cut value for
    // complete string. i.e., str[0..n-1]
    return C[0][n - 1];
}
 
// Driver code
int main()
{
    string str = "ababbbabbababa";
    cout << "Min cuts needed for Palindrome"
            " Partitioning is "
         << minPalPartion(str);
    return 0;
}
 
// This code is contributed by rathbhupendra


C




// Dynamic Programming Solution for Palindrome Partitioning
// Problem
#include <limits.h>
#include <stdio.h>
#include <string.h>
 
// A utility function to get minimum of two integers
int min(int a, int b) { return (a < b) ? a : b; }
 
// Returns the minimum number of cuts needed to partition a
// string such that every part is a palindrome
int minPalPartion(char* str)
{
    // Get the length of the string
    int n = strlen(str);
 
    /* Create two arrays to build the solution in bottom up
       manner C[i][j] = Minimum number of cuts needed for
       palindrome partitioning of substring str[i..j]
       P[i][j] = true if substring str[i..j] is palindrome,
       else false
       Note that C[i][j] is 0 if P[i][j] is true */
    int C[n][n];
    bool P[n][n];
 
    int i, j, k, L; // different looping variables
 
    // Every substring of length 1 is a palindrome
    for (i = 0; i < n; i++) {
        P[i][i] = true;
        C[i][i] = 0;
    }
 
    /* L is substring length. Build the solution in bottom
       up manner by considering all substrings of length
       starting from 2 to n. The loop structure is same as
       Matrix Chain Multiplication problem.
   */
    for (L = 2; L <= n; L++) {
        // For substring of length L, set different possible
        // starting indexes
        for (i = 0; i < n - L + 1; i++) {
            j = i + L - 1; // Set ending index
 
            // If L is 2, then we just need to compare two
            // characters. Else need to check two corner
            // characters and value of P[i+1][j-1]
            if (L == 2)
                P[i][j] = (str[i] == str[j]);
            else
                P[i][j]
                    = (str[i] == str[j]) && P[i + 1][j - 1];
 
            // IF str[i..j] is palindrome, then C[i][j] is 0
            if (P[i][j] == true)
                C[i][j] = 0;
            else {
 
                // Make a cut at every possible location
                // starting from i to j, and get the minimum
                // cost cut.
                C[i][j] = INT_MAX;
                for (k = i; k <= j - 1; k++)
                    C[i][j] = min(
                        C[i][j], C[i][k] + C[k + 1][j] + 1);
            }
        }
    }
 
    // Return the min cut value for complete string. i.e.,
    // str[0..n-1]
    return C[0][n - 1];
}
 
// Driver program to test above function
int main()
{
    char str[] = "ababbbabbababa";
    printf(
        "Min cuts needed for Palindrome Partitioning is %d",
        minPalPartion(str));
    return 0;
}


Java




// Java Code for Palindrome Partitioning
// Problem
public class GFG {
    // Returns the minimum number of cuts needed
    // to partition a string such that every
    // part is a palindrome
    static int minPalPartion(String str)
    {
        // Get the length of the string
        int n = str.length();
 
        /* Create two arrays to build the solution
           in bottom up manner
           C[i][j] = Minimum number of cuts needed
                     for palindrome partitioning
                     of substring str[i..j]
           P[i][j] = true if substring str[i..j] is
                     palindrome, else false
           Note that C[i][j] is 0 if P[i][j] is
           true */
        int[][] C = new int[n][n];
        boolean[][] P = new boolean[n][n];
 
        int i, j, k, L; // different looping variables
 
        // Every substring of length 1 is a palindrome
        for (i = 0; i < n; i++) {
            P[i][i] = true;
            C[i][i] = 0;
        }
 
        /* L is substring length. Build the solution in
         bottom up manner by considering all substrings
         of length starting from 2 to n. The loop
         structure is same as Matrix Chain Multiplication
        )*/
        for (L = 2; L <= n; L++) {
            // For substring of length L, set different
            // possible starting indexes
            for (i = 0; i < n - L + 1; i++) {
                j = i + L - 1; // Set ending index
 
                // If L is 2, then we just need to
                // compare two characters. Else need to
                // check two corner characters and value
                // of P[i+1][j-1]
                if (L == 2)
                    P[i][j]
                        = (str.charAt(i) == str.charAt(j));
                else
                    P[i][j]
                        = (str.charAt(i) == str.charAt(j))
                          && P[i + 1][j - 1];
 
                // IF str[i..j] is palindrome, then
                // C[i][j] is 0
                if (P[i][j] == true)
                    C[i][j] = 0;
                else {
                    // Make a cut at every possible
                    // localtion starting from i to j,
                    // and get the minimum cost cut.
                    C[i][j] = Integer.MAX_VALUE;
                    for (k = i; k <= j - 1; k++)
                        C[i][j] = Integer.min(
                            C[i][j],
                            C[i][k] + C[k + 1][j] + 1);
                }
            }
        }
 
        // Return the min cut value for complete
        // string. i.e., str[0..n-1]
        return C[0][n - 1];
    }
 
    // Driver program to test above function
    public static void main(String args[])
    {
        String str = "ababbbabbababa";
        System.out.println("Min cuts needed for "
                           + "Palindrome Partitioning is "
                           + minPalPartion(str));
    }
}
// This code is contributed by Sumit Ghosh


C#




// C# Code for Palindrome Partitioning
// Problem
using System;
 
class GFG {
    // Returns the minimum number of cuts needed
    // to partition a string such that every
    // part is a palindrome
    static int minPalPartion(String str)
    {
        // Get the length of the string
        int n = str.Length;
 
        /* Create two arrays to build the solution
        in bottom up manner
        C[i][j] = Minimum number of cuts needed
                    for palindrome partitioning
                    of substring str[i..j]
        P[i][j] = true if substring str[i..j] is
                    palindrome, else false
        Note that C[i][j] is 0 if P[i][j] is
        true */
        int[, ] C = new int[n, n];
        bool[, ] P = new bool[n, n];
 
        int i, j, k, L; // different looping variables
 
        // Every substring of length 1 is a palindrome
        for (i = 0; i < n; i++) {
            P[i, i] = true;
            C[i, i] = 0;
        }
 
        /* L is substring length. Build the solution in
        bottom up manner by considering all substrings
        of length starting from 2 to n. The loop
        structure is same as Matrix Chain Multiplication
        */
        for (L = 2; L <= n; L++) {
            // For substring of length L, set different
            // possible starting indexes
            for (i = 0; i < n - L + 1; i++) {
                j = i + L - 1; // Set ending index
 
                // If L is 2, then we just need to
                // compare two characters. Else need to
                // check two corner characters and value
                // of P[i+1][j-1]
                if (L == 2)
                    P[i, j] = (str[i] == str[j]);
                else
                    P[i, j] = (str[i] == str[j])
                              && P[i + 1, j - 1];
 
                // IF str[i..j] is palindrome, then
                // C[i][j] is 0
                if (P[i, j] == true)
                    C[i, j] = 0;
                else {
                    // Make a cut at every possible
                    // location starting from i to j,
                    // and get the minimum cost cut.
                    C[i, j] = int.MaxValue;
                    for (k = i; k <= j - 1; k++)
                        C[i, j] = Math.Min(
                            C[i, j],
                            C[i, k] + C[k + 1, j] + 1);
                }
            }
        }
 
        // Return the min cut value for complete
        // string. i.e., str[0..n-1]
        return C[0, n - 1];
    }
 
    // Driver program
    public static void Main()
    {
        String str = "ababbbabbababa";
        Console.Write("Min cuts needed for "
                      + "Palindrome Partitioning is "
                      + minPalPartion(str));
    }
}
 
// This code is contributed by Sam007


Javascript




<script>
// javascript Code for Palindrome Partitioning
// Problem
  
    // Returns the minimum number of cuts needed
    // to partition a string such that every
    // part is a palindrome
    function minPalPartion( str)
    {
     
        // Get the length of the string
        var n = str.length;
 
        /*
         * Create two arrays to build the solution in bottom up manner C[i][j] = Minimum
         * number of cuts needed for palindrome partitioning of substring str[i..j]
         * P[i][j] = true if substring str[i..j] is palindrome, else false Note that
         * C[i][j] is 0 if P[i][j] is true
         */
        var C = Array(n).fill().map(()=>Array(n).fill(0));
        var P =  Array(n).fill().map(()=>Array(n).fill(false));
 
        var i, j, k, L; // different looping variables
 
        // Every substring of length 1 is a palindrome
        for (i = 0; i < n; i++) {
            P[i][i] = true;
            C[i][i] = 0;
        }
 
        /*
         * L is substring length. Build the solution in bottom up manner by considering
         * all substrings of length starting from 2 to n. The loop structure is same as
         * Matrix Chain Multiplication problem
         */
        for (L = 2; L <= n; L++) {
            // For substring of length L, set different
            // possible starting indexes
            for (i = 0; i < n - L + 1; i++) {
                j = i + L - 1; // Set ending index
 
                // If L is 2, then we just need to
                // compare two characters. Else need to
                // check two corner characters and value
                // of P[i+1][j-1]
                if (L == 2)
                    P[i][j] = (str.charAt(i) == str.charAt(j));
                else
                    P[i][j] = (str.charAt(i) == str.charAt(j)) && P[i + 1][j - 1];
 
                // IF str[i..j] is palindrome, then
                // C[i][j] is 0
                if (P[i][j] == true)
                    C[i][j] = 0;
                else {
                    // Make a cut at every possible
                    // localtion starting from i to j,
                    // and get the minimum cost cut.
                    C[i][j] = Number.MAX_VALUE;
                    for (k = i; k <= j - 1; k++)
                        C[i][j] = Math.min(C[i][j], C[i][k] + C[k + 1][j] + 1);
                }
            }
        }
 
        // Return the min cut value for complete
        // string. i.e., str[0..n-1]
        return C[0][n - 1];
    }
 
    // Driver program to test above function
     
        var str = "ababbbabbababa";
        document.write("Min cuts needed for " + "Palindrome Partitioning is " + minPalPartion(str));
 
// This code is contributed by Rajput-Ji
</script>


PHP




<?php
// Dynamic Programming Solution for Palindrome Partitioning Problem
   
// Returns the minimum number of cuts needed to partition a string
// such that every part is a palindrome
function minPalPartion($str)
{
    // Get the length of the string
    $n = strlen($str);
   
    /* Create two arrays to build the solution in bottom up manner
       C[i][j] = Minimum number of cuts needed for palindrome partitioning
                 of substring str[i..j]
       P[i][j] = true if substring str[i..j] is palindrome, else false
       Note that C[i][j] is 0 if P[i][j] is true */
    $C = array_fill(0, $n, array_fill(0, $n, NULL));
    $P = array_fill(false, $n, array_fill(false, $n, NULL));
   
    // Every substring of length 1 is a palindrome
    for ($i=0; $i<$n; $i++)
    {
        $P[$i][$i] = true;
        $C[$i][$i] = 0;
    }
   
    /* L is substring length. Build the solution in a bottom-up manner by
       considering all substrings of length starting from 2 to n.
       The loop structure is same as Matrix Chain Multiplication problem
       */
    for ($L=2; $L<=$n; $L++)
    {
        // For substring of length L, set different possible starting indexes
        for ($i=0; $i<$n-$L+1; $i++)
        {
            $j = $i+$L-1; // Set ending index
   
            // If L is 2, then we just need to compare two characters. Else
            // need to check two corner characters and value of P[i+1][j-1]
            if ($L == 2)
                $P[$i][$j] = ($str[$i] == $str[$j]);
            else
                $P[$i][$j] = ($str[$i] == $str[$j]) && $P[$i+1][$j-1];
   
            // IF str[i..j] is palindrome, then C[i][j] is 0
            if ($P[$i][$j] == true)
                $C[$i][$j] = 0;
            else
            {
                // Make a cut at every possible location starting from i to j,
                // and get the minimum cost cut.
                $C[$i][$j] = PHP_INT_MAX;
                for ($k=$i; $k<=$j-1; $k++)
                    $C[$i][$j] = min ($C[$i][$j], $C[$i][$k] + $C[$k+1][$j]+1);
            }
        }
    }
   
    // Return the min cut value for complete string. i.e., str[0..n-1]
    return $C[0][$n-1];
}
   
// Driver program to test the above function
 
$str = "ababbbabbababa";
echo "Min cuts needed for Palindrome Partitioning is "
           .minPalPartion($str);
return 0;
?>


Python3




# Dynamic Programming Solution for
# Palindrome Partitioning Problem
 
# Returns the minimum number of
# cuts needed to partition a string
# such that every part is a palindrome
 
 
def minPalPartion(str):
 
    # Get the length of the string
    n = len(str)
 
    # Create two arrays to build the
    # solution in bottom up manner
    # C[i][j] = Minimum number of cuts
    # needed for palindrome
    # partitioning of substring str[i..j]
    # P[i][j] = true if substring str[i..j]
    # is palindrome, else false. Note that
    # C[i][j] is 0 if P[i][j] is true
    C = [[0 for i in range(n)]
         for i in range(n)]
    P = [[False for i in range(n)]
         for i in range(n)]
 
    # different looping variables
    j = 0
    k = 0
    L = 0
 
    # Every substring of length
    # 1 is a palindrome
    for i in range(n):
        P[i][i] = True
        C[i][i] = 0
 
    # L is substring length. Build the
    # solution in bottom-up manner by
    # considering all substrings of
    # length starting from 2 to n.
    # The loop structure is the same as
    # Matrix Chain Multiplication problem
    for L in range(2, n + 1):
 
        # For substring of length L, set
        # different possible starting indexes
        for i in range(n - L + 1):
            j = i + L - 1  # Set ending index
 
            # If L is 2, then we just need to
            # compare two characters. Else
            # need to check two corner characters
            # and value of P[i + 1][j-1]
            if L == 2:
                P[i][j] = (str[i] == str[j])
            else:
                P[i][j] = ((str[i] == str[j]) and
                           P[i + 1][j - 1])
 
            # IF str[i..j] is palindrome,
            # then C[i][j] is 0
            if P[i][j] == True:
                C[i][j] = 0
            else:
 
                # Make a cut at every possible
                # location starting from i to j,
                # and get the minimum cost cut.
                C[i][j] = 100000000
                for k in range(i, j):
                    C[i][j] = min(C[i][j], C[i][k] +
                                  C[k + 1][j] + 1)
 
    # Return the min cut value for
    # complete string. i.e., str[0..n-1]
    return C[0][n - 1]
 
 
# Driver code
str = "ababbbabbababa"
print('Min cuts needed for Palindrome Partitioning is',
      minPalPartion(str))
 
# This code is contributed
# by Sahil shelangia


Output

Min cuts needed for Palindrome Partitioning is 3

Time Complexity: O(n3)
Auxiliary Space: O(n2)

Dynamic Programming Approach for Palindrome Partitioning in (O(n2)):

The problem can be solved by finding the suffix starting from j and ending at index i, (1 <= j <= i <= n – 1), which are palindromes. Hence, we can make a cut here that requires 1 + min cut from rest substring [0, j – 1]. For all such palindromic suffixes starting at j and ending at i, keep minimising in minCutDp[i]. Similarly, we need to compute results for all such i. (1 <= i <= n – 1) and finally, minCutDp[n – 1] will be the minimum number of cuts needed for palindrome partitioning of the given string.

Below is the implementation of the above approach:

C++




#include <bits/stdc++.h>
using namespace std;
 
// Function to generate all possible palindromic substring
bool generatePalindrome(string& s,
                        vector<vector<bool> >& pal)
{
    int n = s.size();
 
    // Initialize the palindrome matrix for single
    // characters
    for (int i = 0; i < n; i++) {
        pal[i][i] = true;
    }
 
    // Iterate over different lengths of substrings
    for (int len = 2; len <= n; len++) {
        // Iterate over the starting positions of substrings
        // of current length
        for (int i = 0; i <= n - len; i++) {
 
            // Calculate the ending position of the
            // substring
            int j = i + len - 1;
 
            // Check if the characters at the starting and
            // ending positions are equal and if the
            // substring between them is a palindrome or a
            // single character
            if (s[i] == s[j]
                && (len == 2 || pal[i + 1][j - 1])) {
 
                // Mark the substring from i to j as a
                // palindrome
                pal[i][j] = true;
            }
        }
    }
}
 
// Function to calculate the minimum number of cuts required
// to make all substrings of 's' palindromic
int minCut(string s)
{
    if (s.empty())
        return 0;
    int n = s.size();
 
    // 2D vector to store whether substring [i, j] is a
    // palindrome
    vector<vector<bool> > pal(n, vector<bool>(n, false));
 
    generatePalindrome(s, pal);
 
    // vector to store minimum cuts required to make
    // substring [i, n-1] palindromic
    vector<int> minCutDp(n, INT_MAX);
 
    // There is no cut required for single character
    // as it is always palindrome
    minCutDp[0] = 0;
 
    // Iterate over the given string
    for (int i = 1; i < n; i++) {
 
        // Check if string 0 to i is palindrome.
        // Then minCut require will be 0.
        if (pal[0][i]) {
            minCutDp[i] = 0;
        }
        else {
            for (int j = i; j >= 1; j--) {
 
                // If s[i] and s[j] are equal and the inner
                // substring [i+1, j-1] is a palindrome or
                // it has a length of 1
                if (pal[j][i]) {
 
                    // Update the minimum cuts required if
                    // cutting at position 'j+1' results in
                    // a smaller value
                    if (minCutDp[j - 1] + 1 < minCutDp[i])
                        minCutDp[i] = minCutDp[j - 1] + 1;
                }
            }
        }
    }
 
    // Return the minimum cuts required for the entire
    // string 's'
    return minCutDp[n - 1];
}
 
int main()
{
    string str = "ababbbabbababa";
 
    int cuts = minCut(str);
    cout << "Minimum cuts required: " << cuts << endl;
    return 0;
}


Java




import java.util.Arrays;
 
public class GFG {
 
    // Function to generate all possible palindromic
    // substrings
    static boolean generatePalindrome(String s,
                                      boolean[][] pal)
    {
        int n = s.length();
 
        // Initialize the palindrome matrix for single
        // characters
        for (int i = 0; i < n; i++) {
            pal[i][i] = true;
        }
 
        // Iterate over different lengths of substrings
        for (int len = 2; len <= n; len++) {
            // Iterate over the starting positions of
            // substrings of current length
            for (int i = 0; i <= n - len; i++) {
 
                // Calculate the ending position of the
                // substring
                int j = i + len - 1;
 
                // Check if the characters at the starting
                // and ending positions are equal and if the
                // substring between them is a palindrome or
                // a single character
                if (s.charAt(i) == s.charAt(j)
                    && (len == 2 || pal[i + 1][j - 1])) {
 
                    // Mark the substring from i to j as a
                    // palindrome
                    pal[i][j] = true;
                }
            }
        }
 
        return true;
    }
 
    // Function to calculate the minimum number of cuts
    // required to make all substrings of 's' palindromic
    static int minCut(String s)
    {
        if (s.isEmpty())
            return 0;
        int n = s.length();
 
        // 2D array to store whether substring [i, j] is a
        // palindrome
        boolean[][] pal = new boolean[n][n];
 
        generatePalindrome(s, pal);
 
        // Array to store minimum cuts required to make
        // substring [i, n-1] palindromic
        int[] minCutDp = new int[n];
        Arrays.fill(minCutDp, Integer.MAX_VALUE);
 
        // There is no cut required for single character
        // as it is always palindrome
        minCutDp[0] = 0;
 
        // Iterate over the given string
        for (int i = 1; i < n; i++) {
 
            // Check if string 0 to i is palindrome.
            // Then minCut require will be 0.
            if (pal[0][i]) {
                minCutDp[i] = 0;
            }
            else {
                for (int j = i; j >= 1; j--) {
 
                    // If s[i] and s[j] are equal and the
                    // inner substring [i+1, j-1] is a
                    // palindrome or it has a length of 1
                    if (pal[j][i]) {
 
                        // Update the minimum cuts required
                        // if cutting at position 'j+1'
                        // results in a smaller value
                        if (minCutDp[j - 1] + 1
                            < minCutDp[i])
                            minCutDp[i]
                                = minCutDp[j - 1] + 1;
                    }
                }
            }
        }
 
        // Return the minimum cuts required for the entire
        // string 's'
        return minCutDp[n - 1];
    }
 
    public static void main(String[] args)
    {
        String str = "ababbbabbababa";
 
        int cuts = minCut(str);
        System.out.println("Minimum cuts required: "
                           + cuts);
    }
}


C#




using System;
 
class Program {
    // Function to generate all possible palindromic
    // substrings
    static void GeneratePalindrome(string s, bool[, ] pal)
    {
        int n = s.Length;
 
        // Initialize the palindrome matrix for single
        // characters
        for (int i = 0; i < n; i++) {
            pal[i, i] = true;
        }
 
        // Iterate over different lengths of substrings
        for (int len = 2; len <= n; len++) {
            // Iterate over the starting positions of
            // substrings of current length
            for (int i = 0; i <= n - len; i++) {
                // Calculate the ending position of the
                // substring
                int j = i + len - 1;
 
                // Check if the characters at the starting
                // and ending positions are equal and if the
                // substring between them is a palindrome or
                // a single character
                if (s[i] == s[j]
                    && (len == 2 || pal[i + 1, j - 1])) {
                    // Mark the substring from i to j as a
                    // palindrome
                    pal[i, j] = true;
                }
            }
        }
    }
 
    // Function to calculate the minimum number of cuts
    // required to make all substrings of 's' palindromic
    static int MinCut(string s)
    {
        if (string.IsNullOrEmpty(s))
            return 0;
        int n = s.Length;
 
        // 2D array to store whether substring [i, j] is a
        // palindrome
        bool[, ] pal = new bool[n, n];
 
        GeneratePalindrome(s, pal);
 
        // Array to store minimum cuts required to make
        // substring [i, n-1] palindromic
        int[] minCutDp = new int[n];
        for (int i = 0; i < n; i++) {
            minCutDp[i] = int.MaxValue;
        }
 
        // There is no cut required for single character as
        // it is always a palindrome
        minCutDp[0] = 0;
 
        // Iterate over the given string
        for (int i = 1; i < n; i++) {
            // Check if string 0 to i is a palindrome. Then
            // minCut required will be 0.
            if (pal[0, i]) {
                minCutDp[i] = 0;
            }
            else {
                for (int j = i; j >= 1; j--) {
                    // If s[i] and s[j] are equal and the
                    // inner substring [i+1, j-1] is a
                    // palindrome or it has a length of 1
                    if (pal[j, i]) {
                        // Update the minimum cuts required
                        // if cutting at position 'j+1'
                        // results in a smaller value
                        if (minCutDp[j - 1] + 1
                            < minCutDp[i])
                            minCutDp[i]
                                = minCutDp[j - 1] + 1;
                    }
                }
            }
        }
 
        // Return the minimum cuts required for the entire
        // string 's'
        return minCutDp[n - 1];
    }
 
    static void Main()
    {
        string str = "ababbbabbababa";
 
        int cuts = MinCut(str);
        Console.WriteLine("Minimum cuts required: " + cuts);
    }
}


Javascript




// JavaScript Code for the above approach
 
function generatePalindrome(s, pal) {
    const n = s.length;
 
    // Initialize the palindrome matrix for single characters
    for (let i = 0; i < n; i++) {
        pal[i][i] = true;
    }
 
    // Iterate over different lengths of substrings
    for (let len = 2; len <= n; len++) {
        // Iterate over the starting positions of substrings of current length
        for (let i = 0; i <= n - len; i++) {
            // Calculate the ending position of the substring
            const j = i + len - 1;
 
            // Check if the characters at the starting and ending positions are equal
            // and if the substring between them is a palindrome or a single character
            if (s[i] === s[j] && (len === 2 || pal[i + 1][j - 1])) {
                // Mark the substring from i to j as a palindrome
                pal[i][j] = true;
            }
        }
    }
}
 
function minCut(s) {
    if (!s) return 0;
    const n = s.length;
 
    // 2D array to store whether substring [i, j] is a palindrome
    const pal = Array.from({ length: n }, () => Array(n).fill(false));
 
    generatePalindrome(s, pal);
 
    // Array to store the minimum cuts required to make substring [i, n-1] palindromic
    const minCutDp = Array(n).fill(Infinity);
 
    // There is no cut required for single character as it is always a palindrome
    minCutDp[0] = 0;
 
    // Iterate over the given string
    for (let i = 1; i < n; i++) {
        // Check if string 0 to i is a palindrome
        // Then minCut required will be 0.
        if (pal[0][i]) {
            minCutDp[i] = 0;
        } else {
            for (let j = i; j >= 1; j--) {
                // If s[i] and s[j] are equal and the inner substring [i+1, j-1]
                // is a palindrome or it has a length of 1
                if (pal[j][i]) {
                    // Update the minimum cuts required if cutting at position 'j+1' results in a smaller value
                    if (minCutDp[j - 1] + 1 < minCutDp[i]) {
                        minCutDp[i] = minCutDp[j - 1] + 1;
                    }
                }
            }
        }
    }
 
    // Return the minimum cuts required for the entire string 's'
    return minCutDp[n - 1];
}
 
const str = "abbac";
const cuts = minCut(str);
document.write("Minimum cuts required:", cuts);
 
// This code is contributed by Abhinav Mahajan (abhinav_m22)


Python3




def generate_palindrome(s, pal):
    n = len(s)
 
    # Initialize the palindrome matrix for single characters
    for i in range(n):
        pal[i][i] = True
 
    # Iterate over different lengths of substrings
    for length in range(2, n + 1):
        # Iterate over the starting positions of substrings of current length
        for i in range(n - length + 1):
            # Calculate the ending position of the substring
            j = i + length - 1
 
            # Check if the characters at the starting and ending positions are equal
            # and if the substring between them is a palindrome or a single character
            if s[i] == s[j] and (length == 2 or pal[i + 1][j - 1]):
                # Mark the substring from i to j as a palindrome
                pal[i][j] = True
 
 
def min_cut(s):
    if not s:
        return 0
    n = len(s)
 
    # 2D list to store whether substring [i, j] is a palindrome
    pal = [[False] * n for _ in range(n)]
 
    generate_palindrome(s, pal)
 
    # List to store minimum cuts required to make substring [i, n-1] palindromic
    min_cut_dp = [float('inf')] * n
 
    # There is no cut required for a single character as it is always a palindrome
    min_cut_dp[0] = 0
 
    # Iterate over the given string
    for i in range(1, n):
        # Check if string 0 to i is a palindrome. Then minCut required will be 0.
        if pal[0][i]:
            min_cut_dp[i] = 0
        else:
            for j in range(i, 0, -1):
                # If s[i] and s[j] are equal and the inner substring [i+1, j-1]
                # is a palindrome or it has a length of 1
                if pal[j][i]:
                    # Update the minimum cuts required if cutting at position 'j+1' results in a smaller value
                    if min_cut_dp[j - 1] + 1 < min_cut_dp[i]:
                        min_cut_dp[i] = min_cut_dp[j - 1] + 1
 
    # Return the minimum cuts required for the entire string 's'
    return min_cut_dp[n - 1]
 
 
# Driver code
if __name__ == "__main__":
    str = "ababbbabbababa"
 
    cuts = min_cut(str)
    print("Minimum cuts required:", cuts)


Output

Minimum cuts required: 3

Time Complexity: O(n2)
Auxiliary Space: O(n2)



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