Submission #1116507

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116507		vomanos	Mobile (BOI12_mobile)	C++14	0 / 100	674 ms	32328 KiB

mobile

// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pdd pair<double, double>

double dist2(pdd a, pdd b) {
	return (a.first - b.first) * (a.first - b.first)
	+ (a.second - b.second) * (a.second - b.second);
}

int main() {
	int N;
	ll L;
	cin >> N >> L;

	pdd s[N];
	for (int i = 0; i < N; i++) cin >> s[i].first >> s[i].second;

	double low = 0, high = 1e12;
	// double low = 6, high = 6.01;
	while (high - low > 0.000001) {
		double mid = low + (high - low) / 2;

		double x = 0;
		for (int i = 0; i < N; i++) {
			if (dist2({x, 0}, {s[i]}) > mid*mid) continue;

			// let x = s[i].first, y = s[i].second;
			// (x + d)^2 + y^2 = r^2
			// x + d = sqrt(r^2 - y^2)
			//d = sqrt(r^2 - y^2)

			x = s[i].first + sqrt(mid*mid - s[i].second * s[i].second);
		}

		// cout << mid << " " << x << endl;

		if (x >= L) high = mid - 1;
		else low = mid + 1;
	}

	cout << fixed << setprecision(10) << low;
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 4
• Subtask 3: 0 / 4
• Subtask 4: 0 / 4
• Subtask 5: 0 / 4
• Subtask 6: 0 / 5
• Subtask 7: 0 / 5
• Subtask 8: 0 / 5
• Subtask 9: 0 / 5
• Subtask 10: 0 / 5
• Subtask 11: 0 / 5
• Subtask 12: 0 / 5
• Subtask 13: 0 / 5
• Subtask 14: 0 / 5
• Subtask 15: 0 / 5
• Subtask 16: 0 / 5
• Subtask 17: 0 / 5
• Subtask 18: 0 / 5
• Subtask 19: 0 / 5
• Subtask 20: 0 / 5
• Subtask 21: 0 / 5