답안 #935534

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
935534	2024-02-29T08:55:50 Z	cryan	Mobile (BOI12_mobile)	C++17	4 / 100	362 ms	67216 KB

mobile

// oh, these hills, they burn so bright / oh, these hills, they bring me life
#include "bits/stdc++.h"
using namespace std;

using ll = long long;
#define all(x) begin(x), end(x)
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)(x.size())
#define inf 1000000010
#define linf 0x3f3f3f3f3f3f3f3f
#define mp make_pair
#define f first
#define s second
#define pi pair<int, int>
#ifdef LOCAL
#include "/mnt/c/yukon/pp.hpp"
#else
#define endl '\n'
#endif

#define double long double
struct Point {
	double x, y;
};

int main() {
	cin.tie(0)->sync_with_stdio(0);

	int n, l;
	cin >> n >> l;

	function<double(Point, Point)> max_point = [&](Point a, Point b) {
		// return (((b.x) * (b.x)) + ((b.y) * (b.y)) - ((a.x) * (a.x)) - ((a.y) * (a.y))) / (2 * (b.x - a.x));
		return (b.x * b.x + b.y * b.y - a.x * a.x - a.y * a.y) / (2 * b.x - 2 * a.x);
	};

	function<double(Point, Point)> dist = [&](Point a, Point b) {
		return sqrt(pow(a.x - b.x, 2) + pow(a.y - b.y, 2));
	};

	vector<Point> stck;
	for (int i = 0; i < n; i++) {
		Point cur;
		cin >> cur.x >> cur.y;
		cur.y = abs(cur.y);

		// take the one with the lowest y coord
		if (sz(stck) && stck.back().x == cur.x) {
			if (cur.y >= stck.back().y) {
				continue;
			} else if (cur.y < stck.back().y) {
				stck.pop_back();
			}
		}

		// find "crosses"
		while (sz(stck) > 1 && max_point(stck[sz(stck) - 2], stck.back()) > max_point(stck.back(), cur)) {
			stck.pop_back();
		}

		stck.push_back(cur);
	}

	double ans = 0;
	for (int x = 0; x < sz(stck); x++) {
		if (stck[x].x < 0 || stck[x].x > l)
			continue;
		Point left = {(x ? max_point(stck[x], stck[x - 1]) : 0), 0};
		if (stck[x - 1].x < 0 || stck[x - 1].x > l)
			left.x = 0;
		Point right = {(x < sz(stck) - 1 ? max_point(stck[x], stck[x + 1]) : l), 0};
		if (stck[x + 1].x < 0 || stck[x + 1].x > l)
			right.x = l;
		if (right.x < 0 || left.x > l)
			continue;

		ans = max({ans, dist(stck[x], left), dist(stck[x], right)});
	}

	cout << fixed << setprecision(6) << ans << endl;
}

// don't get stuck on one approach
// question bounds
// flesh out your approach before implementing o.o
// math it out
// ok well X is always possible, how about X + 1 (etc.)

Subtask #1
0 / 4.0

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

Subtask #2
0 / 4.0

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

Subtask #3
4.0 / 4.0

#	결과	실행 시간	메모리	Grader output
1	Correct	2 ms	344 KB	Output is correct
2	Correct	1 ms	604 KB	Output is correct
3	Correct	1 ms	348 KB	Output is correct
4	Correct	1 ms	604 KB	Output is correct

Subtask #4
0 / 4.0

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

Subtask #5
0 / 4.0

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

Subtask #6
0 / 5.0

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

Subtask #7
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	29 ms	860 KB	Output is correct
2	Incorrect	31 ms	600 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #8
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	27 ms	348 KB	Output is correct
2	Incorrect	25 ms	344 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #9
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Runtime error	33 ms	8040 KB	Execution killed with signal 11
2	Halted	0 ms	0 KB	-

Subtask #10
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Incorrect	35 ms	344 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #11
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	42 ms	2424 KB	Output is correct
2	Incorrect	34 ms	496 KB	Output isn't correct
3	Halted	0 ms	0 KB	-

Subtask #12
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Runtime error	199 ms	32404 KB	Execution killed with signal 11
2	Halted	0 ms	0 KB	-

Subtask #13
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	166 ms	456 KB	Output is correct
2	Correct	182 ms	2588 KB	Output is correct
3	Runtime error	197 ms	8640 KB	Execution killed with signal 11
4	Halted	0 ms	0 KB	-

Subtask #14
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Runtime error	209 ms	41636 KB	Execution killed with signal 11
2	Halted	0 ms	0 KB	-

Subtask #15
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	207 ms	596 KB	Output is correct
2	Correct	227 ms	2508 KB	Output is correct
3	Runtime error	190 ms	5828 KB	Execution killed with signal 11
4	Halted	0 ms	0 KB	-

Subtask #16
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Runtime error	241 ms	45368 KB	Execution killed with signal 11
2	Halted	0 ms	0 KB	-

Subtask #17
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	231 ms	448 KB	Output is correct
2	Correct	286 ms	2428 KB	Output is correct
3	Runtime error	221 ms	8888 KB	Execution killed with signal 11
4	Halted	0 ms	0 KB	-

Subtask #18
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Runtime error	279 ms	54176 KB	Execution killed with signal 11
2	Halted	0 ms	0 KB	-

Subtask #19
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	268 ms	444 KB	Output is correct
2	Correct	294 ms	2616 KB	Output is correct
3	Runtime error	275 ms	8568 KB	Execution killed with signal 11
4	Halted	0 ms	0 KB	-

Subtask #20
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Runtime error	331 ms	67216 KB	Execution killed with signal 11
2	Halted	0 ms	0 KB	-

Subtask #21
0 / 5.0

#	결과	실행 시간	메모리	Grader output
1	Correct	356 ms	448 KB	Output is correct
2	Correct	362 ms	5068 KB	Output is correct
3	Runtime error	360 ms	14036 KB	Execution killed with signal 11
4	Halted	0 ms	0 KB	-

답안 #935534

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