View Code of Problem 120

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

int pri(int n){
    if(n==1){
        return 0;
    }
    int flag=1;
    for(int i=2;i<=sqrt(n);i++){
        if(n%i==0){
            flag=0;
            break;
        }
    }
    return flag;
}

int main()
{
    int h,m,s,h1,m1,h2,m2,sum1,sum2,cnt;
    while(scanf("%d:%d",&h1,&m1)!=EOF){
        scanf("%d:%d",&h2,&m2);
        cnt=0;
        sum1=h1*60+m1;
        sum2=h2*60+m2;
        for(int i=sum1;i<=sum2;i++){
            h=i/60;
            m=i%60;
            s=h*2500+m;
            if(pri(s)==1){
                cnt++;
            }
        }
        printf("%d\n",cnt);
    }
    return 0;
}