답안 #873845

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
873845	2023-11-16T00:38:09 Z	tvladm2009	Mobile (BOI12_mobile)	C++17	12 / 100	157 ms	16356 KB

mobile

#include <bits/stdc++.h>

using i64 = long long;
using ld = double;

ld cross(std::pair<int, int> a, std::pair<int, int> b) {
    int x1 = a.first, x2 = b.first, y1 = a.second, y2 = b.second;
    return 1.0 * (1ll * x2 * x2 + y2 * y2 - 1ll * x1 * x1 - 1ll * y1 * y1) / (2.0 * (x2 - x1));
}

ld solve(ld s, ld e, std::pair<int, int> t) {
    return std::max(std::hypot(s - t.first, t.second), std::hypot(e - t.first, t.second));
}

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

    std::cout << std::fixed << std::setprecision(6);

    int n, L;
    std::cin >> n >> L;
    std::vector<std::pair<int, int>> a(n);
    for (int i = 0; i < n; i++) {
        std::cin >> a[i].first >> a[i].second;
        a[i].second = std::abs(a[i].second);
    }
    std::sort(a.begin(), a.end());
    std::deque<std::pair<int, int>> st;
    for (int i = 0; i < n; i++) {
        int j = i;
        while (j < n && a[j].first == a[i].first) {
            j++;
        }
        while (st.size() >= 2 && cross(st[st.size() - 2], st.back()) > cross(st.back(), a[i])) {
            st.pop_back();
        }
        st.push_back(a[i]);
        i = j - 1;
    }

    ld answer = 0;
    while (st.size() >= 2 && cross(st[0], st[1]) < 0) {
        st.pop_front();
    }
    while (st.size() >= 2 && cross(st[st.size() - 2], st.back()) > L) {
        st.pop_back();
    }
    answer = std::max(answer, solve(0, cross(st[0], st[1]), st[0]));
    answer = std::max(answer, solve(cross(st[st.size() - 2], st.back()), L, st.back()));
    for (int i = 1; i < st.size() - 1; i++) {
        answer = std::max(answer, solve(cross(st[i - 1], st[i]), cross(st[i], st[i + 1]), st[i]));
    }
    std::cout << answer << "\n";
    return 0;
}

Compilation message

mobile.cpp: In function 'int main()':
mobile.cpp:51:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::deque<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |     for (int i = 1; i < st.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~

Subtask #1
4.0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	348 KB	Output is correct
2	Correct	1 ms	500 KB	Output is correct
3	Correct	0 ms	348 KB	Output is correct
4	Correct	0 ms	348 KB	Output is correct

Subtask #2
4.0 / 4.0

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

Subtask #3
4.0 / 4.0

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

Subtask #4
0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	348 KB	Output is correct
2	Correct	1 ms	348 KB	Output is correct
3	Correct	1 ms	500 KB	Output is correct
4	Incorrect	2 ms	344 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #5
0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	348 KB	Output is correct
2	Correct	1 ms	348 KB	Output is correct
3	Correct	1 ms	412 KB	Output is correct
4	Incorrect	1 ms	348 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #6
0 / 5.0

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

Subtask #7
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	1112 KB	Output is correct
2	Incorrect	11 ms	860 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #8
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	1112 KB	Output is correct
2	Correct	11 ms	1024 KB	Output is correct
3	Incorrect	13 ms	860 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #9
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	14 ms	1880 KB	Output is correct
2	Incorrect	12 ms	860 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #10
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Incorrect	15 ms	1112 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #11
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	18 ms	1768 KB	Output is correct
2	Incorrect	15 ms	1116 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #12
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	88 ms	8456 KB	Output is correct
2	Correct	74 ms	4360 KB	Output is correct
3	Correct	71 ms	4184 KB	Output is correct
4	Incorrect	91 ms	4188 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #13
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	75 ms	4188 KB	Output is correct
2	Correct	79 ms	4616 KB	Output is correct
3	Incorrect	64 ms	5128 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #14
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	92 ms	10020 KB	Output is correct
2	Correct	87 ms	4956 KB	Output is correct
3	Correct	87 ms	5144 KB	Output is correct
4	Incorrect	108 ms	4956 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #15
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	89 ms	4956 KB	Output is correct
2	Correct	100 ms	5400 KB	Output is correct
3	Correct	78 ms	5664 KB	Output is correct
4	Incorrect	109 ms	4952 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #16
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	106 ms	11604 KB	Output is correct
2	Correct	105 ms	5724 KB	Output is correct
3	Correct	99 ms	5724 KB	Output is correct
4	Incorrect	127 ms	5720 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #17
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	105 ms	5724 KB	Output is correct
2	Correct	108 ms	6184 KB	Output is correct
3	Incorrect	96 ms	6736 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #18
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	126 ms	13136 KB	Output is correct
2	Correct	115 ms	6488 KB	Output is correct
3	Correct	131 ms	6648 KB	Output is correct
4	Incorrect	145 ms	6648 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #19
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	120 ms	6492 KB	Output is correct
2	Correct	125 ms	6996 KB	Output is correct
3	Incorrect	103 ms	7508 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #20
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	151 ms	16356 KB	Output is correct
2	Correct	145 ms	8284 KB	Output is correct
3	Runtime error	147 ms	16208 KB	Execution killed with signal 11
4	Halted	0 ms	0 KB	-

Subtask #21
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	150 ms	8284 KB	Output is correct
2	Correct	157 ms	8784 KB	Output is correct
3	Incorrect	129 ms	9316 KB	Output isn't correct
4	Halted	0 ms	0 KB	-