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답안 #935521

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
935521 2024-02-29T08:35:00 Z cryan Mobile (BOI12_mobile) C++17
14 / 100
 393 ms 22956 KB 
// 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

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};
		left.x = max(0.0, left.x);
		Point right = {(x < sz(stck) - 1 ? max_point(stck[x], stck[x + 1]) : l), 0};
		right.x = min((double)l, right.x);

		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 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Incorrect 0 ms 348 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 4.0

# 결과 실행 시간 메모리 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 Incorrect 0 ms 348 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #3
4.0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 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

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

Subtask #5
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 344 KB Output isn't correct
4 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 2 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 27 ms 1364 KB Output is correct
2 Incorrect 28 ms 1360 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #8
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 32 ms 1360 KB Output is correct
2 Correct 25 ms 1116 KB Output is correct
3 Correct 31 ms 1376 KB Output is correct
4 Correct 32 ms 1476 KB Output is correct
5 Correct 36 ms 1736 KB Output is correct

Subtask #9
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 3280 KB Output is correct
2 Incorrect 31 ms 1580 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #10
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 42 ms 1968 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #11
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 47 ms 2996 KB Output is correct
2 Incorrect 36 ms 1628 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #12
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 167 ms 12480 KB Output is correct
2 Correct 180 ms 6460 KB Output is correct
3 Correct 172 ms 7508 KB Output is correct
4 Correct 215 ms 9892 KB Output is correct
5 Correct 193 ms 7084 KB Output is correct

Subtask #13
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 185 ms 7072 KB Output is correct
2 Correct 185 ms 7920 KB Output is correct
3 Incorrect 168 ms 7584 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #14
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 206 ms 21564 KB Output is correct
2 Incorrect 213 ms 7724 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #15
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 228 ms 8032 KB Output is correct
2 Correct 221 ms 9140 KB Output is correct
3 Incorrect 197 ms 9372 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #16
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 233 ms 21788 KB Output is correct
2 Incorrect 254 ms 8788 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #17
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 285 ms 9340 KB Output is correct
2 Correct 257 ms 10704 KB Output is correct
3 Incorrect 234 ms 10680 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #18
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 275 ms 22448 KB Output is correct
2 Incorrect 288 ms 10156 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #19
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 305 ms 10540 KB Output is correct
2 Correct 296 ms 11932 KB Output is correct
3 Incorrect 271 ms 12440 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #20
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 334 ms 22956 KB Output is correct
2 Incorrect 361 ms 12496 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #21
0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 393 ms 13208 KB Output is correct
2 Correct 375 ms 15632 KB Output is correct
3 Incorrect 341 ms 16120 KB Output isn't correct
4 Halted 0 ms 0 KB -