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Submission #1098000

# Submission time Handle Problem Language Result Execution time Memory
1098000 2024-10-08T19:25:35 Z 0x34c Mobile (BOI12_mobile) C++17
50 / 100
 1000 ms 125488 KB 
#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define endl '\n'
#define int ll
#define ld long double
#define pdd pair<ld, ld>

using namespace std;

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

ld dist(pii a, ld x)
{
    return sqrt((((ld)a.first) - x) * (((ld)a.first) - x) + (ld)(a.second * a.second));
}

const int INF = 1e9 + 1;
const int INF2 = 1e12;
ld eps = 1e-4;

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

    int N, L;
    cin >> N >> L;

    vector<pii> inp(N);
    map<int, int> closest;
    for (int i = 0; i < N; i++)
    {
        int x, y;
        cin >> x >> y;

        inp[i] = {x, y};

        if (!closest.count(x))
            closest[x] = y;
        else
            closest[x] = (abs(closest[x]) > abs(y) ? y : closest[x]);
    }

    vector<pii> pts;
    for (pii p : closest)
        pts.push_back(p);

    N = pts.size();

    auto calc_bp = [&](int idx1, int idx2)
    {
        ld l = -INF, r = INF;
        while ((r - l) > eps)
        {
            ld m = l + (r - l) / 2;

            ld d1 = dist(pts[idx1], m), d2 = dist(pts[idx2], m);
            if (d1 < d2)
                l = m;
            else
                r = m;
        }

        return l + (r - l) / 2LL;
    };

    stack<int> stk;
    stk.push(0);
    vector<ld> dists, bps;
    for (int i = 1; i < N; i++)
    {
        ld bp = calc_bp(stk.top(), i);

        while (!bps.empty() && bps.back() > bp)
        {
            bps.pop_back();
            stk.pop();
            dists.pop_back();
            bp = calc_bp(stk.top(), i);
        }

        bps.push_back(bp);
        dists.push_back(dist(pts[i], bp));
        stk.push(i);
    }

    ld mx_dist = 0;
    for (int i = 0; i < bps.size(); i++)
    {
        if (bps[i] < 0 || bps[i] > L)
            continue;
        mx_dist = max(mx_dist, dists[i]);
    }

    ld mn_start = INF2, mn_end = INF2;
    for (int i = 0; i < N; i++)
    {
        mn_start = min(mn_start, dist(pts[i], 0));
        mn_end = min(mn_end, dist(pts[i], L));
    }

    mx_dist = max({mx_dist, mn_start, mn_end});
    cout << setprecision(4) << fixed << mx_dist << endl;
}

Compilation message

mobile.cpp: In function 'int main()':
mobile.cpp:92:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long double>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |     for (int i = 0; i < bps.size(); i++)
      |                     ~~^~~~~~~~~~~~

Subtask #1
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 1 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 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 0 ms 348 KB Output is correct

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 348 KB Output is correct
2 Correct 5 ms 860 KB Output is correct
3 Correct 2 ms 348 KB Output is correct
4 Correct 4 ms 724 KB Output is correct

Subtask #4
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 604 KB Output is correct
2 Correct 13 ms 1124 KB Output is correct
3 Correct 2 ms 760 KB Output is correct
4 Correct 15 ms 1124 KB Output is correct

Subtask #5
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 856 KB Output is correct
2 Correct 13 ms 1116 KB Output is correct
3 Correct 2 ms 592 KB Output is correct
4 Correct 15 ms 1028 KB Output is correct

Subtask #6
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 856 KB Output is correct
2 Correct 13 ms 980 KB Output is correct
3 Correct 2 ms 612 KB Output is correct
4 Correct 15 ms 1116 KB Output is correct
5 Correct 3 ms 604 KB Output is correct

Subtask #7
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 198 ms 8656 KB Output is correct
2 Correct 175 ms 7312 KB Output is correct
3 Correct 154 ms 6348 KB Output is correct
4 Correct 221 ms 9668 KB Output is correct
5 Correct 7 ms 1616 KB Output is correct

Subtask #8
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 2904 KB Output is correct
2 Correct 114 ms 5580 KB Output is correct
3 Correct 209 ms 9068 KB Output is correct
4 Correct 233 ms 9932 KB Output is correct
5 Correct 257 ms 10704 KB Output is correct

Subtask #9
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 151 ms 14956 KB Output is correct
2 Correct 167 ms 7072 KB Output is correct
3 Correct 138 ms 13568 KB Output is correct
4 Correct 300 ms 12236 KB Output is correct
5 Correct 71 ms 4312 KB Output is correct

Subtask #10
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 158 ms 7236 KB Output is correct
2 Correct 149 ms 7116 KB Output is correct
3 Correct 53 ms 4688 KB Output is correct
4 Correct 304 ms 12304 KB Output is correct
5 Correct 248 ms 10448 KB Output is correct

Subtask #11
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 223 ms 14216 KB Output is correct
2 Correct 151 ms 7112 KB Output is correct
3 Correct 55 ms 4844 KB Output is correct
4 Correct 304 ms 12228 KB Output is correct
5 Correct 257 ms 10440 KB Output is correct

Subtask #12
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 873 ms 74672 KB Output is correct
2 Correct 181 ms 16724 KB Output is correct
3 Correct 173 ms 16212 KB Output is correct
4 Execution timed out 1056 ms 58524 KB Time limit exceeded
5 Halted 0 ms 0 KB -

Subtask #13
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 194 ms 17236 KB Output is correct
2 Execution timed out 1071 ms 56516 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #14
0 / 5.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1060 ms 104472 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #15
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 205 ms 20304 KB Output is correct
2 Execution timed out 1050 ms 73144 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #16
0 / 5.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1063 ms 113852 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #17
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 221 ms 23376 KB Output is correct
2 Execution timed out 1085 ms 80340 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #18
0 / 5.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1049 ms 122688 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #19
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 241 ms 26452 KB Output is correct
2 Execution timed out 1074 ms 89200 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #20
0 / 5.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1045 ms 125488 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #21
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 281 ms 32932 KB Output is correct
2 Execution timed out 1059 ms 107200 KB Time limit exceeded
3 Halted 0 ms 0 KB -