답안 #481855

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
481855	2021-10-22T03:49:35 Z	sberens	Mobile (BOI12_mobile)	C++17	55 / 100	1000 ms	65464 KB

mobile

#pragma GCC optimize ("fast-math")

#include <bits/stdc++.h>

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <typename K> using hset = gp_hash_table<K, null_type>;
template <typename K, typename V> using hmap = gp_hash_table<K, V>;


using namespace std;

#define all(x) (x).begin(), (x).end()
#define pb push_back
#define eb emplace_back
#define smax(x, y) (x = max(x, y))
#define smin(x, y) (x = min(x, y))

using ld = long double;
using ll = long long;

template <typename T>
using vv = vector<vector<T>>;

using vi = vector<int>;
using ii = array<int, 2>;
using vii = vector<ii>;
using vvi = vv<int>;

using vll = vector<ll>;
using l2 = array<int, 2>;
using vl2 = vector<l2>;
using vvll = vv<ll>;

template <typename T>
using minq = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
using maxq = priority_queue<T>;

const ll M = 1000000007;

#ifndef REFERENCE_DISCRETE_BINARY_SEARCH_H
#define REFERENCE_DISCRETE_BINARY_SEARCH_H


#include <iostream>
#include <functional>


template<typename IN>
IN discrete_binary_search(function<bool(IN)> predicate, IN low = 0, IN high = numeric_limits<IN>::max()) {
    while (fabs(high - low) > 1e-4) {
        IN middle = low + (high - low) / 2; // todo std::midpoint in cpp 2020
        if (predicate(middle))
            high = middle;
        else low = middle;
    }
    return low;
}

#endif //REFERENCE_DISCRETE_BINARY_SEARCH_H

inline bool a_contains_b(array<ld, 2> a,  array<ld, 2> b) {
    return a[0] <= b[0] && b[1] <= a[1];
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int n, l;
    cin >> n >> l;
    vll x(n), y(n);
    for (int i = 0; i < n; ++i) {
        cin >> x[i] >> y[i];
    }

    cout << fixed << setprecision(4) <<  discrete_binary_search<ld>([&](ld d) -> bool {
        // is there a point with min distance > d
        // equivalently, is every point within distance d

        vector<array<ld, 2>> intervals;
        // add to intervals
        for (int i = 0; i < n; ++i) {
            if (abs(y[i]) > d) continue;
            ld dx = sqrt(d * d - y[i] * y[i]);
            // get rid of nested intervals
            array<ld, 2> new_interval{x[i] - dx, x[i] + dx};
            while (!intervals.empty() && a_contains_b(new_interval, intervals.back())) {
                intervals.pop_back();
            }
            if (!(!intervals.empty() && a_contains_b(intervals.back(), new_interval)))
                intervals.pb({x[i] - dx, x[i] + dx});
        }

        // merge intervals
        vector<array<ld, 2>> merged;
        for (auto [s, e] : intervals) {
            if (!merged.empty() && s <= merged.back()[1]) smax(merged.back()[1], e);
            else merged.pb({s, e});
        }
        // check interval spans whole highway
        return any_of(all(merged), [&](array<ld, 2> interval) -> bool {return a_contains_b(interval, {0, (ld) l});});

    }, 0, sqrt(1e18 + 4 * 1e18 + 1e10)) << '\n';

}

Subtask #1
4.0 / 4.0

#	결과	메모리	Grader output
1	Correct	204 KB	Output is correct
2	Correct	204 KB	Output is correct
3	Correct	204 KB	Output is correct
4	Correct	204 KB	Output is correct

Subtask #2
4.0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	1 ms	204 KB	Output is correct
2	Correct	1 ms	204 KB	Output is correct
3	Correct	1 ms	204 KB	Output is correct
4	Correct	1 ms	204 KB	Output is correct

Subtask #3
4.0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	332 KB	Output is correct
2	Correct	6 ms	556 KB	Output is correct
3	Correct	2 ms	332 KB	Output is correct
4	Correct	5 ms	564 KB	Output is correct

Subtask #4
4.0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	6 ms	596 KB	Output is correct
2	Correct	11 ms	808 KB	Output is correct
3	Correct	5 ms	332 KB	Output is correct
4	Correct	4 ms	716 KB	Output is correct

Subtask #5
4.0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	6 ms	620 KB	Output is correct
2	Correct	11 ms	800 KB	Output is correct
3	Correct	3 ms	424 KB	Output is correct
4	Correct	4 ms	716 KB	Output is correct

Subtask #6
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	10 ms	816 KB	Output is correct
2	Correct	11 ms	808 KB	Output is correct
3	Correct	3 ms	332 KB	Output is correct
4	Correct	4 ms	604 KB	Output is correct
5	Correct	4 ms	332 KB	Output is correct

Subtask #7
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	127 ms	7824 KB	Output is correct
2	Correct	77 ms	5252 KB	Output is correct
3	Correct	88 ms	5044 KB	Output is correct
4	Correct	48 ms	3028 KB	Output is correct
5	Correct	26 ms	1148 KB	Output is correct

Subtask #8
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	43 ms	1944 KB	Output is correct
2	Correct	56 ms	4588 KB	Output is correct
3	Correct	52 ms	4960 KB	Output is correct
4	Correct	39 ms	3176 KB	Output is correct
5	Correct	40 ms	2460 KB	Output is correct

Subtask #9
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	250 ms	8636 KB	Output is correct
2	Correct	90 ms	5116 KB	Output is correct
3	Correct	117 ms	8140 KB	Output is correct
4	Correct	37 ms	2272 KB	Output is correct
5	Correct	57 ms	3232 KB	Output is correct

Subtask #10
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	107 ms	4168 KB	Output is correct
2	Correct	104 ms	5168 KB	Output is correct
3	Correct	67 ms	2904 KB	Output is correct
4	Correct	47 ms	2276 KB	Output is correct
5	Correct	59 ms	5588 KB	Output is correct

Subtask #11
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	279 ms	9220 KB	Output is correct
2	Correct	79 ms	5180 KB	Output is correct
3	Correct	64 ms	2896 KB	Output is correct
4	Correct	37 ms	2276 KB	Output is correct
5	Correct	62 ms	5488 KB	Output is correct

Subtask #12
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1084 ms	40420 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #13
5.0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	331 ms	8920 KB	Output is correct
2	Correct	830 ms	40112 KB	Output is correct
3	Correct	382 ms	21128 KB	Output is correct
4	Correct	194 ms	18636 KB	Output is correct
5	Correct	236 ms	21684 KB	Output is correct

Subtask #14
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1093 ms	59168 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #15
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	393 ms	10176 KB	Output is correct
2	Execution timed out	1086 ms	59172 KB	Time limit exceeded
3	Halted	0 ms	0 KB	-

Subtask #16
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1090 ms	60692 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #17
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	451 ms	11828 KB	Output is correct
2	Execution timed out	1082 ms	60576 KB	Time limit exceeded
3	Halted	0 ms	0 KB	-

Subtask #18
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1092 ms	62116 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #19
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	536 ms	13420 KB	Output is correct
2	Execution timed out	1089 ms	62188 KB	Time limit exceeded
3	Halted	0 ms	0 KB	-

Subtask #20
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Execution timed out	1096 ms	65316 KB	Time limit exceeded
2	Halted	0 ms	0 KB	-

Subtask #21
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	648 ms	16456 KB	Output is correct
2	Execution timed out	1084 ms	65464 KB	Time limit exceeded
3	Halted	0 ms	0 KB	-

답안 #481855

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