Generate all rotations of a given string

Given a string S. The task is to print all the possible rotated strings of the given string.

Examples:

Input : S = "geeks"
Output : geeks
         eeksg
         eksge
         ksgee
         sgeek

Input : S = "abc" 
Output : abc
         bca
         cab

Method 1 (Simple): The idea is to run a loop from i = 0 to n – 1 ( n = length of string) i.e for each point of rotation, copy the second part of the string in the temporary string and then copy the first part of the original string to the temporary string.

Below is implementation of the above approach:  

C++

// A simple C++ program to generate all rotations
// of a given string
#include<bits/stdc++.h>
using namespace std;

// Print all the rotated string.
void printRotatedString(char str[])
{
    int len = strlen(str);

    // Generate all rotations one by one and print
    char temp[len];
    for (int i = 0; i < len; i++)
    {
        int j = i;  // Current index in str
        int k = 0;  // Current index in temp

        // Copying the second part from the point
        // of rotation.
        while (str[j] != '\0')
        {
            temp[k] = str[j];
            k++;
            j++;
        }

        // Copying the first part from the point
        // of rotation.
        j = 0;
        while (j < i)
        {
            temp[k] = str[j];
            j++;
            k++;
        }

        printf("%s\n", temp);
    }
}

// Driven Program
int main()
{
    char str[] = "geeks";
    printRotatedString(str);
    return 0;
}

Java

// A simple Java program to generate all rotations
// of a given string

class Test
{
    // Print all the rotated string.
    static void printRotatedString(String str)
    {
        int len = str.length();

        // Generate all rotations one by one and print
        StringBuffer sb;

        for (int i = 0; i < len; i++)
        {
            sb = new StringBuffer();

            int j = i;  // Current index in str
            int k = 0;  // Current index in temp

            // Copying the second part from the point
            // of rotation.
            for (int k2 = j; k2 < str.length(); k2++) {
                sb.insert(k, str.charAt(j));
                k++;
                j++;
            }

            // Copying the first part from the point
            // of rotation.
            j = 0;
            while (j < i)
            {
                sb.insert(k, str.charAt(j));
                j++;
                k++;
            }

            System.out.println(sb);
        }
    }

    // Driver method
    public static void main(String[] args)
    {
        String  str = new String("geeks");
        printRotatedString(str);
    }
}

Python3

# A simple Python3 program to generate
# all rotations of a given string

# Print all the rotated strings.
def printRotatedString(str):

    lenn = len(str)

    # Generate all rotations
    # one by one and print
    temp = [0] * (lenn)
    for i in range(lenn):
        j = i # Current index in str
        k = 0 # Current index in temp

        # Copying the second part from
        # the point of rotation.
        while (j < len(str)):

            temp[k] = str[j]
            k += 1
            j += 1


        # Copying the first part from
        # the point of rotation.
        j = 0
        while (j < i) :

            temp[k] = str[j]
            j += 1
            k += 1


        print(*temp, sep = "")

# Driver Code
if __name__ == '__main__':
    str = "geeks"
    printRotatedString(str)

# This code is contributed
# by SHUBHAMSINGH10

C#

// A simple C# program to generate
// all rotations of a given string
using System;
using System.Text;

class GFG
{
// Print all the rotated string.
public static void printRotatedString(string str)
{
    int len = str.Length;

    // Generate all rotations one
    // by one and print
    StringBuilder sb;

    for (int i = 0; i < len; i++)
    {
        sb = new StringBuilder();

        int j = i; // Current index in str
        int k = 0; // Current index in temp

        // Copying the second part from
        // the point of rotation.
        for (int k2 = j; k2 < str.Length; k2++)
        {
            sb.Insert(k, str[j]);
            k++;
            j++;
        }

        // Copying the first part from
        // the point of rotation.
        j = 0;
        while (j < i)
        {
            sb.Insert(k, str[j]);
            j++;
            k++;
        }

        Console.WriteLine(sb);
    }
}

// Driver Code
public static void Main(string[] args)
{
    string str = "geeks";
    printRotatedString(str);
}
}

// This code is contributed
// by Shrikant13

PHP

<?php
// A simple PHP program to generate
// all rotations of a given string

// Print all the rotated string.
function printRotatedString($str)
{
    $len = strlen($str);

    // Generate all rotations one
    // by one and print
    $temp = " ";
    for ($i = 0; $i < $len; $i++)
    {
        $j = $i; // Current index in str
        $k = 0;  // Current index in temp

        // Copying the second part from
        // the point of rotation.
        while ($j < $len)
        {
            $temp[$k] = $str[$j];
            $k++;
            $j++;
        }

        // Copying the first part from
        // the point of rotation.
        $j = 0;
        while ($j < $i)
        {
            $temp[$k] = $str[$j];
            $j++;
            $k++;
        }

        echo $temp . "\n";
    }
}

// Driver Code
$str = "geeks";
printRotatedString($str);

// This code is contributed
// by Akanksha Rai
?>

Javascript

<script>

// A simple javascript program to generate
// all rotations of a given string

// Print all the rotated string.
function printRotatedString(str)
{
    var len = str.length;

    // Generate all rotations one
    // by one and print
    var sb;

    for(i = 0; i < len; i++)
    {
        sb = [];

        // Current index in str
        var j = i;

        // Current index in temp
        var k = 0;

        // Copying the second part from the point
        // of rotation.
        for(k2 = j; k2 < str.length; k2++)
        {
            sb.push(str.charAt(j));
            k++;
            j++;
        }

        // Copying the first part from the point
        // of rotation.
        j = 0;

        while (j < i)
        {
            sb.push(str.charAt(j));
            j++;
            k++;
        }
        document.write(sb.join("") + "<br>");
    }
}

// Driver code
var  str = "geeks";
printRotatedString(str);

// This code is contributed by Amit Katiyar

</script>

Output

geeks
eeksg
eksge
ksgee
sgeek

Time complexity: O(n²) where n is length of string
Auxiliary Space: O(n)

Method 2 (Tricky and Efficient): The idea is based on the efficient method to check if strings are rotations of each other or not. We concatenate str with itself, i.e., we do str.str where . is concatenation operator. Now we traverse the concatenated string from 0 to n – 1 and print all substrings of size n.

Below is the implementation of above approach:  

C++

// An efficient C++ program to print all
// rotations of a string.
#include<bits/stdc++.h>
using namespace std;

// Print all the rotated string.
void printRotatedString(char str[])
{
    int n = strlen(str);

    // Concatenate str with itself
    char temp[2*n + 1];
    strcpy(temp, str);
    strcat(temp, str);

    // Print all substrings of size n.
    // Note that size of temp is 2n
    for (int i = 0; i < n; i++)
    {
        for (int j=0; j != n; j++)
            printf("%c",temp[i + j]);
        printf("\n");
    }
}

// Driven Program
int main()
{
    char str[] = "geeks";
    printRotatedString(str);
    return 0;
}

Java

// A simple Java program to generate all rotations
// of a given string

class Test
{
    // Print all the rotated string.
    static void printRotatedString(String str)
    {
        int n = str.length();

        StringBuffer sb = new StringBuffer(str);
        // Concatenate str with itself
        sb.append(str);

        // Print all substrings of size n.
        // Note that size of sb is 2n
        for (int i = 0; i < n; i++)
        {
            for (int j=0; j != n; j++)
                System.out.print(sb.charAt(i + j));
            System.out.println();
        }
    }

    // Driver method
    public static void main(String[] args)
    {
        String  str = new String("geeks");
        printRotatedString(str);
    }
}

Python3

# An efficient Python3 program to print
# all rotations of a string.

# Print all the rotated string.
def printRotatedString(string) :

    n = len(string)

    # Concatenate str with itself
    temp = string + string

    # Print all substrings of size n.
    # Note that size of temp is 2n
    for i in range(n) :

        for j in range(n) :
            print(temp[i + j], end = "")

        print()

# Driver Code
if __name__ == "__main__" :

    string = "geeks"
    printRotatedString(string)

# This code is contributed by Ryuga

C#

// A simple C# program to generate all rotations
// of a given string
using System;
using System.Text;

class Test
{

    // Print all the rotated string.
    static void printRotatedString(String str)
    {
        int n = str.Length;

        StringBuilder sb = new StringBuilder(str);
        // Concatenate str with itself
        sb.Append(str);

        // Print all substrings of size n.
        // Note that size of sb is 2n
        for (int i = 0; i < n; i++)
        {
            for (int j=0; j != n; j++)
                Console.Write(sb[i + j]);
            Console.WriteLine();
        }
    }

    // Driver method
    public static void Main(String[] args)
    {
        String str = "geeks";
        printRotatedString(str);
    }
}

PHP

<?php
// An efficient PHP program to print all
// rotations of a string.

// Print all the rotated string.
function printRotatedString($str)
{
    $n = strlen($str);

    // Concatenate str with itself
    $temp=$str.$str;

    // Print all substrings of size n.
    // Note that size of temp is 2n
    for ($i = 0; $i < $n; $i++)
    {
        for ($j = 0; $j != $n; $j++)
            print($temp[$i + $j]);
        print("\n");
    }
}

    // Driver code
    $str = "geeks";
    printRotatedString($str);

// This code is contributed by mits
?>

Javascript

<script>
// A simple javascript program to generate all rotations
// of a given string

    // Print all the rotated string.
    function printRotatedString(str)
    {
        var n = str.length;
        var sb = str;

        // Concatenate str with itself
        sb += (str);

        // Print all substrings of size n.
        // Note that size of sb is 2n
        for (var i = 0; i < n; i++)
        {
            for (var j = 0; j != n; j++)
                document.write(sb.charAt(i + j));
            document.write('<br>');
        }
    }

    // Driver method
    var  str = "geeks";
    printRotatedString(str);

// This code is contributed by 29AjayKumar
</script>

Output

geeks
eeksg
eksge
ksgee
sgeek

Time complexity: O(n²) where n is length of string
Auxiliary Space : O(n)

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