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답안 #1011174

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1011174 2024-06-30T03:44:26 Z vjudge1 Mobile (BOI12_mobile) C++17
66 / 100
 314 ms 19620 KB 
#include <bits/stdc++.h>
using i64 = long long;

struct Point {
    double x, y;
};

double dist(const Point &a, const Point &b) {
    double dx = a.x - b.x;
    double dy = a.y - b.y;
    return std::sqrt(dx * dx + dy * dy);
}

double insec(const Point &a, const Point &b) {
    double t1 = b.x * b.x + b.y * b.y - a.x * a.x - a.y * a.y;
    double t2 = b.x - a.x;
    return t1 / t2 / 2;
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int n;
    double l;
    std::cin >> n >> l;

    std::deque<Point> pt;
    for (int i = 0; i < n; i++) {
        double x, y;
        std::cin >> x >> y;
        y = std::abs(y);

        if (pt.size() && pt.back().x == x) {
            if (pt.back().y <= y) {
                continue;
            } else {
                pt.pop_back();
            }
        }

        Point cur{x, y};
        while ((int)pt.size() > 1 && insec(pt[pt.size() - 1], pt[pt.size() - 2]) > insec(pt[pt.size() - 1], cur)) {
            pt.pop_back();
        }

        pt.emplace_back(cur);
    }

    while ((int)pt.size() > 1 && insec(pt[0], pt[1]) < 0) {
        pt.pop_front();
    }
    while ((int)pt.size() > 1 && insec(pt[pt.size() - 1], pt[pt.size() - 2]) > l) {
        pt.pop_back();
    }

    double ans = 0;
    Point lt{0, 0}, rt{l, 0};
    for (int i = 0; i < (int)pt.size(); i++) {
        if (i > 0) {
            lt.x = insec(pt[i], pt[i - 1]);
        }
        if (i + 1 < (int)pt.size()) {
            rt.x = insec(pt[i], pt[i + 1]);
        }
        if (lt.x < 0 || lt.x > l || rt.x < 0 || rt.x > l) {
            continue;
        }
        ans = std::max({ans, dist(lt, pt[i]), dist(pt[i], rt)});
    }
    std::cout << std::fixed << std::setprecision(6) << ans << "\n";

    return 0;
}

Subtask #1
4.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 408 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 344 KB Output is correct

Subtask #2
4.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct

Subtask #3
0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Incorrect 1 ms 348 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
4.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 348 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 2 ms 464 KB Output is correct

Subtask #5
4.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 344 KB Output is correct
2 Correct 2 ms 532 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 2 ms 348 KB Output is correct

Subtask #6
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 344 KB Output is correct
2 Correct 2 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 3 ms 540 KB Output is correct
5 Correct 2 ms 348 KB Output is correct

Subtask #7
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 20 ms 348 KB Output is correct
2 Correct 23 ms 1332 KB Output is correct
3 Correct 19 ms 860 KB Output is correct
4 Correct 23 ms 1584 KB Output is correct
5 Correct 12 ms 600 KB Output is correct

Subtask #8
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 19 ms 348 KB Output is correct
2 Correct 20 ms 1116 KB Output is correct
3 Correct 23 ms 1456 KB Output is correct
4 Correct 29 ms 1628 KB Output is correct
5 Correct 28 ms 1880 KB Output is correct

Subtask #9
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 22 ms 1884 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #10
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 28 ms 348 KB Output is correct
2 Correct 26 ms 460 KB Output is correct
3 Correct 24 ms 1624 KB Output is correct
4 Correct 35 ms 2396 KB Output is correct
5 Correct 28 ms 1724 KB Output is correct

Subtask #11
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 1372 KB Output is correct
2 Correct 27 ms 1628 KB Output is correct
3 Correct 23 ms 1628 KB Output is correct
4 Correct 33 ms 2348 KB Output is correct
5 Correct 28 ms 1628 KB Output is correct

Subtask #12
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 117 ms 8604 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #13
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 119 ms 348 KB Output is correct
2 Correct 134 ms 7684 KB Output is correct
3 Correct 119 ms 7684 KB Output is correct
4 Correct 167 ms 9556 KB Output is correct
5 Correct 146 ms 7504 KB Output is correct

Subtask #14
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 146 ms 10212 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #15
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 138 ms 348 KB Output is correct
2 Correct 155 ms 1220 KB Output is correct
3 Correct 148 ms 8276 KB Output is correct
4 Correct 183 ms 12112 KB Output is correct
5 Correct 159 ms 9132 KB Output is correct

Subtask #16
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 167 ms 11844 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #17
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 181 ms 348 KB Output is correct
2 Correct 188 ms 10576 KB Output is correct
3 Correct 203 ms 10836 KB Output is correct
4 Correct 210 ms 13652 KB Output is correct
5 Correct 209 ms 10324 KB Output is correct

Subtask #18
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 200 ms 13536 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #19
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 243 ms 344 KB Output is correct
2 Correct 216 ms 11972 KB Output is correct
3 Correct 185 ms 11860 KB Output is correct
4 Correct 259 ms 15696 KB Output is correct
5 Correct 221 ms 11860 KB Output is correct

Subtask #20
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 258 ms 16724 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #21
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 242 ms 348 KB Output is correct
2 Correct 294 ms 14684 KB Output is correct
3 Correct 247 ms 15236 KB Output is correct
4 Correct 314 ms 19620 KB Output is correct
5 Correct 262 ms 15188 KB Output is correct