UVaOJ 568 - Just the Facts

gistfile1.c

/* UVaOJ 568 - Just the Facts */
#include <stdio.h>

int main(void)
{
	int N = 0;
	
	while( scanf("%d", &N)==1 )
	{
		int i = 0;
		long long facts = 1;
		
		for(i = 1;i < N+1;i++)
		{
			facts *= i;
			while(facts%10 == 0) facts /= 10;   // 舍弃末尾所有的〇
			facts %= 100000000;    // 取最后8位
		}
		
		printf("%5d -> %lld\n", N, facts%10);
	}
	
	return 0;
}