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답안 #844013

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
844013 2023-09-04T21:56:09 Z cryan Mecho (IOI09_mecho) C++17
86 / 100
 1000 ms 8660 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

 
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
struct Event {
	int locf, locs;
	int dist;
};
int grid[801][801], dist_bees[801][801];

const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};
int main() {
	cin.tie(0)->sync_with_stdio(0);

	int n;
	cin >> n;

	int S;
	cin >> S;

	vector<pi> hives;
	pi start, end;

	for (int i = 0; i < n; i++) {
		string st;
		cin >> st;

		for (int j = 0; j < n; j++) {
			if (st[j] == 'T')
				grid[i][j] = -1;
			else if (st[j] != 'D')
				grid[i][j] = 0;
			else
				grid[i][j] = 1, end = {i, j};

			if (st[j] == 'H') {
				hives.emplace_back(i, j);
			} else if (st[j] == 'M')
				start = {i, j};
		}
	}

	// let's get distance from bees first
	queue<Event> bfs;
	memset(dist_bees, 0x3f, sizeof dist_bees);

	for (auto &[i, j] : hives) {
		bfs.push({i, j, 0});
		dist_bees[i][j] = 0;
	}
	while (!bfs.empty()) {
		int i = bfs.front().locf;
		int j = bfs.front().locs;
		int dist = bfs.front().dist;
		bfs.pop();

		if (dist_bees[i][j] < dist)
			continue;

		for (int d = 0; d < 4; d++) {
			int new_i = i + dx[d], new_j = j + dy[d];

			if (new_i >= 0 && new_i < n && new_j >= 0 && new_j < n) {
				if (grid[new_i][new_j] == 0 && dist_bees[new_i][new_j] > dist + 1) {
					dist_bees[new_i][new_j] = dist + 1;
					bfs.push({new_i, new_j, dist + 1});
				}
			}
		}
	}
	// for (int i = 0; i < n; i++) {
	// 	cout << dist_bees[i] << endl;
	// }

	// now mecho's turn
	bfs.push({start.f, start.s, 0});
	// just store distance w/o S factor
	vector<vector<int>> mecho_dist(n, vector<int>(n, -inf));
	mecho_dist[start.f][start.s] = dist_bees[start.f][start.s];

	while (sz(bfs)) {
		int i = bfs.front().locf;
		int j = bfs.front().locs;
		int dist = bfs.front().dist;
		bfs.pop();
		if (mecho_dist[i][j] > dist_bees[i][j] - (dist) / S)
			continue;
		int elapsed = (dist + 1) / S;
		for (int d = 0; d < 4; d++) {
			int ni = i + dx[d], nj = j + dy[d];

			if (ni < 0 || ni >= n || nj < 0 || nj >= n)
				continue;

			// if (ni == 3 && nj == 3) {
			// 	cout << dist + 1 << ' ' << elapsed << ' ' << dist_bees[ni][nj] << endl;
			// }
			int lead = min(mecho_dist[i][j], dist_bees[ni][nj] - elapsed);
			if (grid[ni][nj] == 0 && mecho_dist[ni][nj] < lead && elapsed < dist_bees[ni][nj]) {
				mecho_dist[ni][nj] = lead;
				bfs.push({ni, nj, dist + 1});
			}
		}
	}
	// cout << "________" << endl;
	// for (int i = 0; i < n; i++) {
	// 	cout << mecho_dist[i] << endl;
	// }
	// cout << "________" << endl;
	// for (int i = 0; i < n; i++) {
	// 	cout << mecho_lead[i] << endl;
	// }

	int ans = -inf;
	for (int d = 0; d < 4; d++) {
		int ni = end.f + dx[d], nj = end.s + dy[d];

		if (ni < 0 || ni >= n || nj < 0 || nj >= n)
			continue;
		if (grid[ni][nj] == -1 || mecho_dist[ni][nj] == inf)
			continue;

		ans = max(ans, mecho_dist[ni][nj] - 1);
		// int elapsed = (mecho_dist[ni][nj] + S) / S;
		// ans = max(ans, dist_bees[ni][nj] - elapsed);
	}
	if (ans < 0) {
		cout << -1 << endl;
	} else {
		cout << 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
86.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 4696 KB Output is correct
2 Correct 1 ms 4696 KB Output is correct
3 Correct 1 ms 4696 KB Output is correct
4 Correct 1 ms 4700 KB Output is correct
5 Correct 1 ms 4696 KB Output is correct
6 Correct 1 ms 4696 KB Output is correct
7 Correct 59 ms 8052 KB Output is correct
8 Correct 1 ms 4696 KB Output is correct
9 Correct 1 ms 4952 KB Output is correct
10 Correct 1 ms 4696 KB Output is correct
11 Correct 1 ms 4700 KB Output is correct
12 Correct 1 ms 4700 KB Output is correct
13 Correct 1 ms 4696 KB Output is correct
14 Correct 1 ms 4700 KB Output is correct
15 Correct 1 ms 4696 KB Output is correct
16 Correct 1 ms 4696 KB Output is correct
17 Correct 1 ms 4696 KB Output is correct
18 Correct 1 ms 4696 KB Output is correct
19 Correct 1 ms 4696 KB Output is correct
20 Correct 1 ms 4696 KB Output is correct
21 Correct 1 ms 4696 KB Output is correct
22 Correct 1 ms 4696 KB Output is correct
23 Correct 1 ms 4696 KB Output is correct
24 Correct 1 ms 4696 KB Output is correct
25 Correct 1 ms 4700 KB Output is correct
26 Correct 1 ms 4696 KB Output is correct
27 Correct 1 ms 4696 KB Output is correct
28 Correct 1 ms 4696 KB Output is correct
29 Correct 1 ms 4708 KB Output is correct
30 Correct 1 ms 4696 KB Output is correct
31 Correct 1 ms 4700 KB Output is correct
32 Correct 1 ms 4696 KB Output is correct
33 Correct 4 ms 5208 KB Output is correct
34 Correct 5 ms 5212 KB Output is correct
35 Correct 219 ms 5300 KB Output is correct
36 Correct 4 ms 5208 KB Output is correct
37 Correct 6 ms 5208 KB Output is correct
38 Correct 330 ms 5456 KB Output is correct
39 Correct 5 ms 5464 KB Output is correct
40 Correct 7 ms 5464 KB Output is correct
41 Correct 467 ms 5596 KB Output is correct
42 Correct 7 ms 5720 KB Output is correct
43 Correct 9 ms 5724 KB Output is correct
44 Correct 644 ms 5968 KB Output is correct
45 Correct 9 ms 5720 KB Output is correct
46 Correct 11 ms 5720 KB Output is correct
47 Correct 865 ms 6248 KB Output is correct
48 Correct 9 ms 6232 KB Output is correct
49 Correct 12 ms 6232 KB Output is correct
50 Execution timed out 1051 ms 6624 KB Time limit exceeded
51 Correct 12 ms 6488 KB Output is correct
52 Correct 16 ms 6488 KB Output is correct
53 Execution timed out 1002 ms 7376 KB Time limit exceeded
54 Correct 12 ms 7000 KB Output is correct
55 Correct 20 ms 7000 KB Output is correct
56 Execution timed out 1071 ms 7828 KB Time limit exceeded
57 Correct 18 ms 7516 KB Output is correct
58 Correct 20 ms 7516 KB Output is correct
59 Execution timed out 1043 ms 8276 KB Time limit exceeded
60 Correct 17 ms 8024 KB Output is correct
61 Correct 23 ms 8048 KB Output is correct
62 Execution timed out 1040 ms 8660 KB Time limit exceeded
63 Correct 37 ms 8024 KB Output is correct
64 Correct 41 ms 8024 KB Output is correct
65 Correct 41 ms 7820 KB Output is correct
66 Correct 41 ms 8032 KB Output is correct
67 Correct 34 ms 8032 KB Output is correct
68 Correct 26 ms 8156 KB Output is correct
69 Correct 29 ms 7856 KB Output is correct
70 Correct 27 ms 7864 KB Output is correct
71 Correct 30 ms 8272 KB Output is correct
72 Correct 31 ms 8016 KB Output is correct
73 Correct 27 ms 8024 KB Output is correct
74 Correct 74 ms 7992 KB Output is correct
75 Correct 28 ms 7992 KB Output is correct
76 Correct 38 ms 8024 KB Output is correct
77 Correct 38 ms 8024 KB Output is correct
78 Correct 29 ms 7932 KB Output is correct
79 Correct 438 ms 8292 KB Output is correct
80 Correct 58 ms 8016 KB Output is correct
81 Correct 32 ms 8024 KB Output is correct
82 Correct 123 ms 8096 KB Output is correct
83 Correct 42 ms 7872 KB Output is correct
84 Correct 108 ms 8028 KB Output is correct
85 Correct 245 ms 8152 KB Output is correct
86 Correct 280 ms 8452 KB Output is correct
87 Correct 67 ms 8028 KB Output is correct
88 Correct 162 ms 8152 KB Output is correct
89 Correct 569 ms 8312 KB Output is correct
90 Correct 41 ms 8024 KB Output is correct
91 Correct 73 ms 8076 KB Output is correct
92 Correct 42 ms 8028 KB Output is correct