Thread: reverse digits of a number

Write a function to reverse a number by eliminating duplicates in it?
Ex:
input : 2452
output : 254

The idea is to have an array of size 10 (having all digits from 0-9) which keeps a note of whether any digit has its duplicate.

Code:

int Reverse(int num)
{
	int mod=0, ret=0;
	int arr[10]={0};
	while(num) {
		mod=num%10;
		if(arr[mod]==0) {
			arr[mod]=1;
			ret=ret*10+mod;
		}
		num=num/10;
	}
	return ret;
}