c语言基础题关于时间问题

代码如下：
#include<stdio.h>
int main(){
int t1,t2,h1,m1;
scanf("%d %d",&t1,&t2);
h1=t1/100;
m1=t1%100;
if(t2>=0){
h1=h1+(m1+t2)/60;
m1=(m1+t2)%60;
}
else{
int con=h1*60+m1+t2;
h1=con/60;
m1=con%60;
}
printf("%d%02d",h1,m1);
return 0;
}