Write a program in C to display the number in reverse order

.#include <iostream>
using namespace std;
void main()
{
int num,r,sum=0,t;

    cout<<"Input a number: ";
    cin>>num;

    for(t=num;num!=0;num=num/10){
         r=num % 10;
         sum=sum*10+r;
    }
    cout<<"The number in reverse order is : "<<sum;
      system ("pause");
}

Test Data : 

Input a number: 12345 

Expected Output :

The number in reverse order is : 54321