제출 #914989

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
914989		Em1L	Mobile (BOI12_mobile)	C++17	100 / 100	617 ms	26088 KiB

mobile

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

using ll = long long;
using pii = pair<int, int>;
using tiiii = tuple<int, int, ll, ll>;

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);

    int n, L; cin >> n >> L;

    vector < ll > x(n), y(n);

    for (int i = 0; i < n; i++)
        cin >> x[i] >> y[i];

    auto Good = [&](double dist) {
        double r = 0;

        for (int i = 0; i < n; i++) {
            if (y[i] > dist)
                continue;

            double left = x[i] - sqrt(dist * dist - y[i] * y[i]);
            double right = x[i] + sqrt(dist * dist - y[i] * y[i]);

            if (left <= r)
                r = max(r, right);
        }

        return r >= L;
    };

    double l = 1, m, r = 2e+9;

    while (r - l > 1e-3) {
        m = (l + r) / 2;

        if (Good(m))
            r = m;
        else
            l = m;
    }

    cout << setprecision(4) << fixed << (l + r) / 2 << "\n";
}

• 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