#include<stdio.h> int prime(int n){ int i,flag=1; if(n==2||n==3) flag=1; else{ for(i=2;i<n;i++) if(n%2==0){ flag=0; break; } } return flag; } void main(){ int h1,h2,m1,m2,s; int i,count,x,y,sum; while(scanf("%02d:%02d",&h1,&m1)!=EOF){ scanf("%02d:%02d",&h2,&m2); sum=0; count=h2*60+m2-(h1*60+m1); for(i=0;i<count;i++){ x=h1+(m2+i)/60; y=(m2+i)%60; s=x*2500+y; if(prime(s)==1) sum++; } printf("%d\n",sum); } } |
Double click to view unformatted code.