Generate all rotations of a given string

Difficulty Level : Easy
Last Updated : 26 Apr, 2019

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

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

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 implementation of this 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 
?> 

Output:

geeks
eeksg
eksge
ksgee
sgeek

Method 1 (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 implementation of this 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 
?> 

Output:

geeks
eeksg
eksge
ksgee
sgeek

This article is contributed by Anuj Chauhan. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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Related Articles

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

Python3

C#

PHP

C++

Java

Python3

C#

PHP