将小时转化分钟即可
#include<stdio.h>
int main()
{
int hour,min;
int hour1,min1;
int a,b,c;
scanf("%d %d/n",&hour,&min);
scanf("%d %d/n",&hour1,&min1);
a=hour1-hour;
b=min1-min;
c=a*60+b;
printf("%d",c);

}