[백준] 2004번 : 조합 0의 개수 - C

https://www.acmicpc.net/problem/2004

#include<stdio.h>
#include <string.h>

int main() {
    int n,m;
    scanf("%d %d",&n,&m);
    int count2=0;
    int count5=0;
    for(long i=2;i<=n;i*=2) count2+=n/i;
    for(long i=2;i<=m;i*=2) count2-=m/i;
    for(long i=2;i<=n-m;i*=2) count2-=(n-m)/i;
        
    for(long i=5;i<=n;i*=5) count5+=n/i;
    for(long i=5;i<=m;i*=5) count5-=m/i;
    for(long i=5;i<=n-m;i*=5) count5-=(n-m)/i;
    
    printf("%d", count2<=count5 ? count2 : count5);
}