oj.uz

Submission #843979

# Submission time Handle Problem Language Result Execution time Memory
843979 2023-09-04T19:16:09 Z cryan Mecho (IOI09_mecho) C++17
26 / 100
 42 ms 11604 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 Event {
	pi loc;
	int dist;
};
const vector<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<vector<int>> grid(n, vector<int>(n));
	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;

	vector<vector<int>> dist_bees(n, vector<int>(n, inf));
	for (auto &[i, j] : hives) {
		bfs.push({{i, j}, 0});
		dist_bees[i][j] = 0;
	}
	while (!bfs.empty()) {
		auto [i, j] = bfs.front().loc;
		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] != -1 && dist_bees[new_i][new_j] > dist + 1 && pi{new_i, new_j} != end) {
					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));
	vector<vector<int>> mecho_lead(n, vector<int>(n, 0));
	mecho_dist[start.f][start.s] = 0;
	mecho_lead[start.f][start.s] = dist_bees[start.f][start.s] - 1;

	while (sz(bfs)) {
		auto [i, j] = bfs.front().loc;
		int dist = bfs.front().dist;
		bfs.pop();
		if (mecho_dist[i][j] < dist)
			continue;
		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;

			int elapsed = (dist + S) / S;
			if (grid[ni][nj] != -1 && mecho_dist[ni][nj] > dist + 1 && elapsed < dist_bees[ni][nj]) {
				mecho_dist[ni][nj] = dist + 1;
				mecho_lead[ni][nj] = min(dist_bees[ni][nj] - elapsed, mecho_lead[i][j]);
				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_lead[ni][nj]);
		// int elapsed = (mecho_dist[ni][nj] + S) / S;
		// ans = max(ans, dist_bees[ni][nj] - elapsed);
	}
	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
26.0 / 100.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 348 KB Output isn't correct
2 Incorrect 0 ms 348 KB Output isn't correct
3 Incorrect 0 ms 348 KB Output isn't correct
4 Incorrect 0 ms 348 KB Output isn't correct
5 Incorrect 0 ms 348 KB Output isn't correct
6 Correct 0 ms 348 KB Output is correct
7 Incorrect 32 ms 11196 KB Output isn't correct
8 Incorrect 0 ms 344 KB Output isn't correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Incorrect 0 ms 348 KB Output isn't correct
15 Incorrect 0 ms 348 KB Output isn't correct
16 Correct 0 ms 348 KB Output is correct
17 Incorrect 0 ms 348 KB Output isn't correct
18 Correct 0 ms 348 KB Output is correct
19 Incorrect 0 ms 452 KB Output isn't correct
20 Correct 0 ms 348 KB Output is correct
21 Incorrect 0 ms 452 KB Output isn't correct
22 Correct 0 ms 348 KB Output is correct
23 Incorrect 0 ms 348 KB Output isn't correct
24 Correct 0 ms 348 KB Output is correct
25 Incorrect 0 ms 528 KB Output isn't correct
26 Correct 0 ms 348 KB Output is correct
27 Incorrect 0 ms 348 KB Output isn't correct
28 Correct 1 ms 348 KB Output is correct
29 Incorrect 1 ms 348 KB Output isn't correct
30 Correct 1 ms 348 KB Output is correct
31 Incorrect 0 ms 348 KB Output isn't correct
32 Correct 0 ms 348 KB Output is correct
33 Incorrect 4 ms 2352 KB Output isn't correct
34 Correct 4 ms 2336 KB Output is correct
35 Incorrect 5 ms 2336 KB Output isn't correct
36 Incorrect 4 ms 3160 KB Output isn't correct
37 Correct 5 ms 3024 KB Output is correct
38 Incorrect 7 ms 3164 KB Output isn't correct
39 Incorrect 5 ms 3676 KB Output isn't correct
40 Correct 6 ms 3676 KB Output is correct
41 Incorrect 9 ms 3828 KB Output isn't correct
42 Incorrect 6 ms 4512 KB Output isn't correct
43 Correct 7 ms 4560 KB Output is correct
44 Incorrect 10 ms 4716 KB Output isn't correct
45 Incorrect 11 ms 5724 KB Output isn't correct
46 Correct 9 ms 5468 KB Output is correct
47 Incorrect 12 ms 5564 KB Output isn't correct
48 Incorrect 9 ms 6488 KB Output isn't correct
49 Correct 10 ms 6492 KB Output is correct
50 Incorrect 15 ms 6344 KB Output isn't correct
51 Incorrect 10 ms 7516 KB Output isn't correct
52 Correct 11 ms 7592 KB Output is correct
53 Incorrect 16 ms 7516 KB Output isn't correct
54 Incorrect 11 ms 8540 KB Output isn't correct
55 Correct 14 ms 8540 KB Output is correct
56 Incorrect 26 ms 9044 KB Output isn't correct
57 Incorrect 14 ms 9820 KB Output isn't correct
58 Correct 15 ms 9820 KB Output is correct
59 Incorrect 22 ms 9808 KB Output isn't correct
60 Incorrect 16 ms 11260 KB Output isn't correct
61 Correct 17 ms 11100 KB Output is correct
62 Incorrect 32 ms 11192 KB Output isn't correct
63 Incorrect 32 ms 11052 KB Output isn't correct
64 Correct 42 ms 11240 KB Output is correct
65 Correct 40 ms 11100 KB Output is correct
66 Incorrect 39 ms 11248 KB Output isn't correct
67 Incorrect 33 ms 11060 KB Output isn't correct
68 Incorrect 30 ms 11088 KB Output isn't correct
69 Correct 32 ms 11088 KB Output is correct
70 Correct 30 ms 11260 KB Output is correct
71 Correct 29 ms 11072 KB Output is correct
72 Correct 31 ms 11088 KB Output is correct
73 Correct 29 ms 11604 KB Output is correct
74 Correct 39 ms 11100 KB Output is correct
75 Correct 26 ms 11100 KB Output is correct
76 Correct 25 ms 11308 KB Output is correct
77 Correct 29 ms 11100 KB Output is correct
78 Incorrect 26 ms 11168 KB Output isn't correct
79 Incorrect 40 ms 11100 KB Output isn't correct
80 Correct 28 ms 11172 KB Output is correct
81 Correct 28 ms 11088 KB Output is correct
82 Incorrect 29 ms 11172 KB Output isn't correct
83 Incorrect 26 ms 11100 KB Output isn't correct
84 Incorrect 38 ms 11100 KB Output isn't correct
85 Incorrect 28 ms 11100 KB Output isn't correct
86 Incorrect 30 ms 11344 KB Output isn't correct
87 Incorrect 28 ms 11100 KB Output isn't correct
88 Incorrect 32 ms 11272 KB Output isn't correct
89 Incorrect 40 ms 11220 KB Output isn't correct
90 Incorrect 28 ms 11092 KB Output isn't correct
91 Incorrect 32 ms 11092 KB Output isn't correct
92 Incorrect 28 ms 11028 KB Output isn't correct