C program to find reverse of a number

#include<stdio.h>
int main()
{
  int m,n,r;
  printf("\nEnter a number:=");
  scanf("%d",&n); //123
  r=0;
  while(n>0)
  {
    m=n%10; //3 2 1
    r=r*10+m; //3 32 321
    n=n/10; //12 1 0
  }
  printf("\nReverse=%d",r);
  return  0;
}

Explanation
/*
n=123
r=0
m=3
r=3
n=12
m=2
r=32
n=1
m=1
r=321
n=0
*/