C++ Call by reference | Gammaprep solution

#include <iostream>
using namespace std;


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

void reverse_dig(int &a,int &b)
{
    //Add your code here.
    int x=0,y=0;
    while(a!=0){
        x = x*10 + (a%10);
        a/=10;
    }
    while(b!=0){
        y = y*10 + (b%10);
        b/=10;
    }
    a= x;
    b = y;

    return;
}
void swap(int &a,int &b)
{
    int c;
    c = a;
    a = b;
    b=c;
    return;
    //Add your code here.
}


// { Driver Code Starts.

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int a, b;
        cin>>a>>b;

        reverse_dig(a,b);
        swap(a,b);
        cout<<a<<" "<<b<<endl;
    }
    return 0;
}  //