Sort012.cpp

// You are given an integer array/list(ARR) of size N. It contains only 0s, 1s and 2s. Write a solution to sort this array/list in a 'single scan'.
// 'Single Scan' refers to iterating over the array/list just once or to put it in other words, you will be visiting each element in the array/list just once.
// Note:
// You need to change in the given array/list itself. Hence, no need to return or print anything. 

// Sample Input 1:
// 1
// 7
// 0 1 2 0 2 0 1
// Sample Output 1:
// 0 0 0 1 1 2 2 

// My Code:
void sort012(int *arr, int n)  {  
    int count0 = 0,count1 = 0, count2 = 0;
    for(int i = 0; i < n; i++){    //count 0   
        if(arr[i] == 0){
            count0++;
        }
        if(arr[i] == 1){    //count 1
            count1++;
        }  
    }
    
    for(int i=0;i<count0;i++){    //print 0
        arr[i]=0;
    }
    int temp = count0 + count1;
     for(int i=count0;i<temp;i++){    //print 1
        arr[i]=1;
    }
     for(int i=temp;i<n;i++){    //print 2
        arr[i]=2;
    }
}

// Main Code:
#include <iostream>
#include <algorithm>
using namespace std;

#include "solution.h"

int main()
{
	int t;
	cin >> t;
	while (t--)
	{
		int size;

		cin >> size;
		int *arr = new int[size];

		for (int i = 0; i < size; i++)
		{
			cin >> arr[i];
		}

		sort012(arr, size);

		for (int i = 0; i < size; i++)
		{
			cout << arr[i] << " ";
		}

		delete[] arr;
		cout << endl;
	}
	return 0;
}