Given a string str and the task is to modify the string such that no three consecutive characters are same. In a single operation, any character can be inserted at any position in the string. Find the minimum number of such operations required.
Examples:
Input : str = “aabbbcc”
Output: 1
“aabbdbcc” is the modified string.Input: str = “geeksforgeeks”
Output: 0
Approach: For every three consecutive characters which are same, a single character has to be inserted in between them to make any three consecutive characters different. But the number of operations needs to be minimized so the character must be inserted after the second character. For example, if the string is “bbbb” then if the character is inserted at the second position i.e. “babbb” then there are still three consecutive same characters and another operation is required to resolve that but if the character was inserted at the third position i.e. “bbabb” then only a single operation is required.
Below is the implementation of the above approach:
C++
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // Function to return the count of characters // that are to be inserted in str such that no // three consecutive characters are same int getCount(string str, int n) { // To store the count of // operations required int cnt = 0; int i = 0; while (i < n - 2) { // A character needs to be // inserted after str[i + 1] if (str[i] == str[i + 1] && str[i] == str[i + 2]) { cnt++; i = i + 2; } // Current three consecutive // characters are not same else i++; } return cnt; } // Driver code int main() { string str = "aabbbcc"; int n = str.length(); cout << getCount(str, n); return 0; } |
Java
// Java implementation of the approach import java.util.*; class GFG { // Function to return the count of characters // that are to be inserted in str such that no // three consecutive characters are same static int getCount(char[] str, int n) { // To store the count of // operations required int cnt = 0; int i = 0; while (i < n - 2) { // A character needs to be // inserted after str[i + 1] if (str[i] == str[i + 1] && str[i] == str[i + 2]) { cnt++; i = i + 2; } // Current three consecutive // characters are not same else { i++; } } return cnt; } // Driver code static public void main(String[] arg) { String str = "aabbbcc"; int n = str.length(); System.out.println(getCount(str.toCharArray(), n)); } } // This code is contributed by PrinciRaj1992 |
Python3
# Python3 implementation of the approach # Function to return the count of characters # that are to be inserted in str1 such that no # three consecutive characters are same def getCount(str1, n): # To store the count of # operations required cnt = 0; i = 0; while (i < n - 2): # A character needs to be # inserted after str1[i + 1] if (str1[i] == str1[i + 1] and str1[i] == str1[i + 2]): cnt += 1 i = i + 2 # Current three consecutive # characters are not same else: i += 1 return cnt # Driver code str1 = "aabbbcc"n = len(str1) print(getCount(str1, n)) # This code is contributed by Mohit Kumar |
C#
// C# implementation of the above approach using System; class GFG { // Function to return the count of characters // that are to be inserted in str such that no // three consecutive characters are same static int getCount(string str, int n) { // To store the count of // operations required int cnt = 0; int i = 0; while (i < n - 2) { // A character needs to be // inserted after str[i + 1] if (str[i] == str[i + 1] && str[i] == str[i + 2]) { cnt++; i = i + 2; } // Current three consecutive // characters are not same else { i++; } } return cnt; } // Driver code static public void Main () { string str = "aabbbcc"; int n = str.Length; Console.WriteLine(getCount(str, n)); } } // This code is contributed by AnkitRai01 |
1
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