백준 1072 c++ 이분탐색

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
#define ll long long




int main() {
	cin.tie(0)->sync_with_stdio(0);
	
	long x, y;
	cin >> x >> y;
	int z = (y*100) / x;
	if (z >= 99) {
		cout << -1;
		return 0;
	}
	int left = 0;
	int right = 9876543210;
	int ans = -1;
	while (left <= right) {
		int mid = (left + right) / 2;
		int temp = (100 * (y + mid)) / (x + mid);
		if (z >= temp) {
			ans = mid + 1;
			left = mid + 1;
		}
		else {
			right = mid - 1;
		}

	}
	cout << ans << "\n";
	return 0;
}