求大佬解答

#include<bits/stdc++.h>
using namespace std ;
int main(){
	int s , v  ; 
	scanf("%d %d" , &s , &v) ;
	int need_time = ceil(s / v) + 10 ;
	int have_time = 80 * 60 ;
	need_time > have_time ? have_time += 24 * 60 : have_time *= 1 ;
	have_time -= need_time ;
	int hour = floor(have_time / 60) ; 
	int minute = have_time - hour * 60 ;
	hour %= 24 ;
	hour < 10 ? printf("%c%d" , '0' , hour) : printf("%d" , hour) ;
	cout<<":";
	minute < 10 ? printf("%c%d" , '0' , minute) : printf("%d" , minute) ;
	return 0 ; 
}