Segregate 0s and 1s.cpp

//{ Driver Code Starts
//Initial template for C++

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

// } Driver Code Ends
//User function template for C++

class Solution{   
public:
    void segregate0and1(int arr[], int n) {
        // code here
        int l = 0, r = n-1;
 
    while (l < r)
    {
        while (arr[l] == 0 && l < r)
            l++;
        while (arr[r] == 1 && l < r)
            r--;
 
        if (l < r)
        {
            arr[l] = 0;
            arr[r] = 1;
            l++;
            r--;
        }
    }
    }
};

//{ Driver Code Starts.

int main() {
    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        int arr[n];
        for (int i = 0; i < n; i++) {
            cin >> arr[i];
        }
        Solution ob;
        ob.segregate0and1(arr, n);
        for (int i = 0; i < n; i++) {
            cout << arr[i] << " ";
        }
        cout << "\n";
    }
    return 0;
}
// } Driver Code Ends