C++ Program To Print All Permutations Of A Given String

// C++ program to print all permutations 
// with duplicates allowed 
#include <bits/stdc++.h> 
using namespace std; 

// Function to print permutations 
// of string 
// This function takes three parameters: 
// 1. String 
// 2. Starting index of the string 
// 3. Ending index of the string. 
void permute(string a, int l, int r) 
{ 
    // Base case 
    if (l == r) 
        cout<<a<<endl; 
    else
    { 
        // Permutations made 
        for (int i = l; i <= r; i++) 
        { 
            // Swapping done 
            swap(a[l], a[i]); 

            // Recursion called 
            permute(a, l+1, r); 

            //backtrack 
            swap(a[l], a[i]); 
        } 
    } 
} 

// Driver Code 
int main() 
{ 
    string str = "ABC"; 
    int n = str.size(); 
    permute(str, 0, n-1); 
    return 0; 
} 
// This is code is contributed by rathbhupendra 

// C++ program to implement
// the above approach
#include <bits/stdc++.h>
#include <string>
using namespace std;

void permute(string s, 
             string answer)
{
    if(s.length() == 0)
    {
        cout << answer << "  ";
        return;
    }
    for(int i = 0; 
            i < s.length(); i++)
    {
        char ch = s[i];
        string left_substr = s.substr(0, i);
        string right_substr = s.substr(i + 1);
        string rest = left_substr + right_substr;
        permute(rest , answer+ch);
    }
}

// Driver code
int main()
{
    string s;
    string answer = "";

    cout << "Enter the string : ";
    cin >> s;

    cout << 
    "All possible strings are : ";
    permute(s, answer);
    return 0;
}