Submission #970784

#	Time	Username	Problem	Language	Result	Execution time	Memory
970784		hihihihaw	Mobile (BOI12_mobile)	C++17	100 / 100	340 ms	35456 KiB

mobile

#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;

pair<long long, long long> p[1000000];

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n, len;
	cin >> n >> len;
	for (int i = 0; i < n; i++) cin >> p[i].x >> p[i].y;

	double l = 1, r = 1.5e9;
	while (r - l > 1e-3) {
		double mid = (l + r) / 2, curr = 0;
		for (int i = 0; i < n; i++) {
			double delta = sqrt(mid * mid - p[i].y * p[i].y);
			double a = p[i].x - delta, b = p[i].x + delta;
			if (a <= curr) curr = max(curr, b);
		}

		if (curr >= len) r = mid;
		else l = mid;
	}

	cout << fixed << setprecision(4) << l;
	return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 5 / 5
• Subtask 11: 5 / 5
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5