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Submission #873846

# Submission time Handle Problem Language Result Execution time Memory
873846 2023-11-16T00:39:22 Z tvladm2009 Mobile (BOI12_mobile) C++14
12 / 100
 232 ms 16480 KB 
#include <bits/stdc++.h>

using i64 = long long;
using ld = long 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]));
    }
    answer = (ld) ((ld) ((ld) answer * (int) 1e6) / (int) 1e6);
    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

# Verdict Execution time Memory 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 #2
4.0 / 4.0

# Verdict Execution time Memory 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 344 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory 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 Correct 1 ms 348 KB Output is correct

Subtask #4
0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 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 #5
0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 344 KB Output is correct
2 Correct 1 ms 348 KB Output is correct
3 Correct 2 ms 348 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

# Verdict Execution time Memory 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

# Verdict Execution time Memory Grader output
1 Correct 11 ms 1112 KB Output is correct
2 Incorrect 12 ms 860 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #8
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 1112 KB Output is correct
2 Correct 12 ms 856 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

# Verdict Execution time Memory Grader output
1 Correct 24 ms 1884 KB Output is correct
2 Incorrect 13 ms 856 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #10
0 / 5.0

# Verdict Execution time Memory Grader output
1 Incorrect 16 ms 1116 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #11
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 1764 KB Output is correct
2 Incorrect 15 ms 1112 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #12
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 117 ms 8216 KB Output is correct
2 Correct 85 ms 4432 KB Output is correct
3 Correct 73 ms 4360 KB Output is correct
4 Incorrect 91 ms 4184 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #13
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 76 ms 4188 KB Output is correct
2 Correct 82 ms 4628 KB Output is correct
3 Incorrect 75 ms 5124 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #14
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 144 ms 10064 KB Output is correct
2 Correct 89 ms 4956 KB Output is correct
3 Correct 87 ms 4956 KB Output is correct
4 Incorrect 123 ms 4956 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #15
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 92 ms 4956 KB Output is correct
2 Correct 97 ms 5412 KB Output is correct
3 Correct 91 ms 5464 KB Output is correct
4 Incorrect 110 ms 4956 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #16
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 164 ms 11576 KB Output is correct
2 Correct 109 ms 5724 KB Output is correct
3 Correct 102 ms 5928 KB Output is correct
4 Incorrect 132 ms 5724 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #17
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 110 ms 5724 KB Output is correct
2 Correct 114 ms 6284 KB Output is correct
3 Incorrect 105 ms 6956 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #18
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 186 ms 13136 KB Output is correct
2 Correct 118 ms 6488 KB Output is correct
3 Correct 117 ms 6488 KB Output is correct
4 Incorrect 149 ms 6488 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #19
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 123 ms 6492 KB Output is correct
2 Correct 129 ms 6980 KB Output is correct
3 Incorrect 111 ms 7508 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #20
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 232 ms 16480 KB Output is correct
2 Correct 153 ms 8284 KB Output is correct
3 Runtime error 155 ms 16224 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #21
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 159 ms 8284 KB Output is correct
2 Correct 161 ms 8808 KB Output is correct
3 Incorrect 138 ms 9548 KB Output isn't correct
4 Halted 0 ms 0 KB -