Implementation issue

#1

[https://sapphireengine.com/@/cx264f]
This is my implementation of the question when I submitted it in hackerblocks https://hack.codingblocks.com/app/practice/1/300/problem
3 of my test case passed but 3 did not I am unable to find the issue in my code

#2

hello @rahulmutreja76 there was problem of constraints only .
as the test cases are larger .
here is the correct code :
#include
using namespace std;
#define int long long int
bool isPossible(int students, int coupons, int perCoupon, int studentCoupon, int mid) {
if (mid * perCoupon <= coupons + (students - mid) * studentCoupon)
return true;
return false;
}

int32_t main() {
int students, coupons, perCoupon, studentCoupon;
cin >> students >> coupons >> perCoupon>>studentCoupon;

int start = 1, end = students, ans = 0;
while (start <= end) {
	int mid = (start+end)/2;
	if(isPossible(students, coupons, perCoupon, studentCoupon, mid)) {
		ans = mid;
		start = mid + 1;
	}
	else
		end = mid - 1;
}
cout << ans;
return 0;

}