Permutations of given String Last Updated : 23 Jul, 2025 Comments Improve Suggest changes Like Article Like Report Try it on GfG Practice Given a string s, the task is to return all permutations of a given string in lexicographically sorted order.Note: A permutation is the rearrangement of all the elements of a string. Duplicate arrangement can exist.Examples:Input: s = "ABC"Output: "ABC", "ACB", "BAC", "BCA", "CAB", "CBA"Input: s = "XY"Output: "XY", "YX"Input: s = "AAA"Output: "AAA", "AAA", "AAA", "AAA", "AAA", "AAA" The idea is to use backtracking to generate all possible permutations of given string s. To do so, first initialize an array of string ans[] to store all the permutations. Start from the 0th index and for each index i, swap the value s[i] with all the elements in its right i.e. from i+1 to n-1, and recur to the index i + 1. If the index i is equal to n, store the resultant string in ans[], else keep operating similarly for all other indices. Thereafter, swap back the values to original values to initiate backtracking. At last sort the array ans[].illustration: Below is the implementation of the above approach: C++ // C++ Program to generate all unique // permutations of a string #include <bits/stdc++.h> using namespace std; // Recursive function to generate // all permutations of string s void recurPermute(int index, string &s, vector<string> &ans) { // Base Case if (index == s.size()) { ans.push_back(s); return; } // Swap the current index with all // possible indices and recur for (int i = index; i < s.size(); i++) { swap(s[index], s[i]); recurPermute(index + 1, s, ans); swap(s[index], s[i]); } } // Function to find all unique permutations vector<string> findPermutation(string &s) { // Stores the final answer vector<string> ans; recurPermute(0, s, ans); // sort the resultant vector sort(ans.begin(), ans.end()); return ans; } int main() { string s = "ABC"; vector<string> res = findPermutation(s); for(auto x: res) { cout << x << " "; } return 0; } Java // Java Program to generate all unique // permutations of a string import java.util.*; class GfG { // Recursive function to generate // all permutations of string s static void recurPermute(int index, StringBuilder s, List<String> ans) { // Base Case if (index == s.length()) { ans.add(s.toString()); return; } // Swap the current index with all // possible indices and recur for (int i = index; i < s.length(); i++) { swap(s, index, i); recurPermute(index + 1, s, ans); swap(s, index, i); } } // Swap characters at positions i and j static void swap(StringBuilder s, int i, int j) { char temp = s.charAt(i); s.setCharAt(i, s.charAt(j)); s.setCharAt(j, temp); } // Function to find all unique permutations static List<String> findPermutation(String s) { // Stores the final answer List<String> ans = new ArrayList<>(); StringBuilder str = new StringBuilder(s); recurPermute(0, str, ans); // sort the resultant list Collections.sort(ans); return ans; } public static void main(String[] args) { String s = "ABC"; List<String> res = findPermutation(s); for (String x : res) { System.out.print(x + " "); } } } Python # Python Program to generate all unique # permutations of a string # Recursive function to generate # all permutations of string s def recurPermute(index, s, ans): # Base Case if index == len(s): ans.append("".join(s)) return # Swap the current index with all # possible indices and recur for i in range(index, len(s)): s[index], s[i] = s[i], s[index] recurPermute(index + 1, s, ans) s[index], s[i] = s[i], s[index] # Function to find all unique permutations def findPermutation(s): # Stores the final answer ans = [] recurPermute(0, list(s), ans) # sort the resultant list ans.sort() return ans if __name__ == "__main__": s = "ABC" res = findPermutation(s) for x in res: print(x, end=" ") C# // C# Program to generate all unique // permutations of a string using System; using System.Collections.Generic; class GfG { // Recursive function to generate // all permutations of string s static void recurPermute(int index, char[] s, List<string> ans) { // Base Case if (index == s.Length) { ans.Add(new string(s)); return; } // Swap the current index with all // possible indices and recur for (int i = index; i < s.Length; i++) { Swap(s, index, i); recurPermute(index + 1, s, ans); Swap(s, index, i); } } // Swap characters at positions i and j static void Swap(char[] s, int i, int j) { char temp = s[i]; s[i] = s[j]; s[j] = temp; } // Function to find all unique permutations static List<string> findPermutation(string s) { // Stores the final answer List<string> ans = new List<string>(); recurPermute(0, s.ToCharArray(), ans); // sort the resultant list ans.Sort(); return ans; } static void Main(string[] args) { string s = "ABC"; List<string> res = findPermutation(s); foreach (string x in res) { Console.Write(x + " "); } } } JavaScript // JavaScript Program to generate all unique // permutations of a string // Recursive function to generate // all permutations of string s function recurPermute(index, s, ans) { // Base Case if (index === s.length) { ans.add(s.join("")); return; } // Swap the current index with all // possible indices and recur for (let i = index; i < s.length; i++) { [s[index], s[i]] = [s[i], s[index]]; recurPermute(index + 1, s, ans); [s[index], s[i]] = [s[i], s[index]]; } } // Function to find all unique permutations function findPermutation(s) { // sort input string s = s.split("").sort(); // Stores all unique permutations let res = new Set(); recurPermute(0, s, res); // Convert Set to Array for the final answer return Array.from(res).sort(); } const s = "ABC"; const res = findPermutation(s); console.log(res.join(" ")); OutputABC ACB BAC BCA CAB CBA Time Complexity: O(n * n!) Auxiliary Space: O(n!)Related articles:Print all distinct permutations of a given string with duplicates. Permutations of a given string using STL Write a program to print all permutations of a given string Comment More infoAdvertise with us Next Article Types of Asymptotic Notations in Complexity Analysis of Algorithms K kartik Follow Improve Article Tags : Strings Greedy Backtracking Mathematical Combinatorial Recursion DSA Amazon Samsung Walmart Cisco Citrix Snapdeal Accolite MAQ Software OYO permutation Apple strings +15 More Practice Tags : AccoliteAmazonAppleCiscoCitrixMAQ SoftwareSamsungSnapdealWalmartBacktrackingCombinatorialGreedyMathematicalpermutationRecursionStringsStrings +13 More Similar Reads Basics & PrerequisitesTime Complexity and Space ComplexityMany times there are more than one ways to solve a problem with different algorithms and we need a way to compare multiple ways. 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