Different Methods to Reverse a String in C++

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s = "Hello World";

    // Using reverse() function to reverse s
    reverse(s.begin(), s.end());

    cout << s;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s = "Hello World";

    // Creating a temporary reversed string
  	// and assigning it to the s
    s = string(s.rbegin(), s.rend());
    
  	cout << s;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s = "Hello World";
    stack<char> st;

    // Push each character of string into stack
    for (char c : s)
        st.push(c);

    // Clear the string
    s.clear();

    // Pop characters from stack and add them to
    // reversed string
    while (!st.empty()) {
        s.push_back(st.top());
        st.pop();
    }

    cout << s;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;

int main() {
    string s = "Hello World";

    // Initialize two pointers: left at start
    //  and right at the end of the string
    int l = 0;
    int r = s.length() - 1;

    // Loop until the two pointers meet in the middle
    while (l < r) {
      
        // Swap characters at position left and right
        swap(s[l], s[r]);

        // Move the left pointer to right
        l++;

        // Move the right pointer to left
        r--;
    }

    cout << s;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;

// Function to reverse the string using recursion
void revStr(string &s, int l, int r) {
  
    // Base case: When left and right pointer meet
    if (l >= r)
        return;

    // Swap characters at left and right
    swap(s[l], s[r]);

    // Recursive call to reverse remaining substring
    revStr(s, l + 1, r - 1);
}

int main() {
    string s = "Hello World";

    // Call the recursive function to reverse string
    revStr(s, 0, s.length() - 1);

    cout << s;
    return 0;
}