답안 #623053

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
623053	2022-08-05T06:38:23 Z	54skyxenon	Mobile (BOI12_mobile)	C++17	8 / 100	1000 ms	40300 KB

mobile

// https://oj.uz/problem/view/BOI12_mobile

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

#define EPS 0.0001
#define pdd pair<double, double>
#define mp make_pair

int n, l;
vector<int> X, Y;

vector<pdd> merge(vector<pdd>& intervals) {
    sort(intervals.begin(), intervals.end());

    vector<pdd> new_intervals;
    for (auto [start, end] : intervals) {
        if (new_intervals.empty() || new_intervals.rbegin()->second < start) {
            new_intervals.push_back(mp(start, end));
        }
        else {
            new_intervals.rbegin()->second = max(new_intervals.rbegin()->second, end);
        }
    }
    
    return new_intervals;
}

bool ok(double radius) {
    vector<pdd> intervals({mp(0, 0), mp(l, l)});
    
    for (int i = 0; i < n; i++) {
        double x1 = X[i], y1 = Y[i];
    
        double term = (radius * radius) - (y1 * y1);
        if (term >= 0) {
            double term_sqrt = sqrt(term);
            intervals.push_back(mp(x1 - term_sqrt, x1 + term_sqrt));
        }
    }
        
    intervals = merge(intervals);

    for (int i = 0; i < intervals.size() - 1; i++) {
        double midpt = (intervals[i].second + intervals[i + 1].first) / 2;
        if (0 <= midpt && midpt <= l) {
            return true;
        }
    }

    return false;
}

int main() {
    cin >> n >> l;

    X.resize(n);
    Y.resize(n);
    for (int i = 0; i < n; i++) {
        cin >> X[i] >> Y[i];
    }

    double lo = 0.0;
    double hi = l;

    int threshold = 100;
    while (threshold--) {
        double mid = (lo + hi) / 2;

        if (!ok(mid)) {
            hi = mid;
        }
        else {
            lo = mid;
        }
    }

    cout << lo << endl;
}

Compilation message

mobile.cpp: In function 'bool ok(double)':
mobile.cpp:44:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<double, double> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for (int i = 0; i < intervals.size() - 1; i++) {
      |                     ~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
4.0 / 4.0

#	결과	메모리	Grader output
1	Correct	212 KB	Output is correct
2	Correct	212 KB	Output is correct
3	Correct	212 KB	Output is correct
4	Correct	212 KB	Output is correct

Subtask #2
4.0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	0 ms	212 KB	Output is correct
2	Correct	1 ms	212 KB	Output is correct
3	Correct	1 ms	212 KB	Output is correct
4	Correct	1 ms	212 KB	Output is correct

Subtask #3
0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	3 ms	340 KB	Output is correct
2	Correct	8 ms	340 KB	Output is correct
3	Correct	2 ms	340 KB	Output is correct
4	Incorrect	12 ms	416 KB	Output isn't correct
5	Halted	0 ms	0 KB	-

Subtask #4
0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	5 ms	340 KB	Output is correct
2	Incorrect	18 ms	536 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #5
0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	5 ms	448 KB	Output is correct
2	Incorrect	21 ms	920 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #6
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	35 ms	548 KB	Output is correct
2	Incorrect	20 ms	552 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #7
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	288 ms	4160 KB	Output is correct
2	Incorrect	590 ms	4396 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #8
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	55 ms	2044 KB	Output is correct
2	Correct	59 ms	2116 KB	Output is correct
3	Incorrect	66 ms	2076 KB	Output isn't correct
4	Halted	0 ms	0 KB	-

Subtask #9
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	825 ms	4452 KB	Output is correct
2	Incorrect	662 ms	4344 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #10
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Incorrect	641 ms	4816 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #11
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Incorrect	779 ms	4944 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #12
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1092 ms	20264 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #13
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1082 ms	20512 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #14
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1088 ms	30896 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #15
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1082 ms	30944 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #16
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1092 ms	33244 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #17
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1060 ms	33224 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #18
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1077 ms	35660 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #19
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1089 ms	35656 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #20
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1049 ms	40244 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #21
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1061 ms	40300 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-