oj.uz

Submission #843169

# Submission time Handle Problem Language Result Execution time Memory
843169 2023-09-03T18:34:21 Z Mizo_Compiler Tracks in the Snow (BOI13_tracks) C++
100 / 100
 476 ms 94296 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double ld;
#define pb push_back
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define F first
#define S second
const int N = 4000;
int n, m, ans = 1;
char c[N][N];
bool fc[N][N];
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
vector<pair<int, int>> f, r;
bool vis[N][N];

void dfs(int i, int j) {
	stack<pair<int, int>> q;
  	q.push({i, j});
  	while (!q.empty()) {
      i = q.top().F, j = q.top().S;
      q.pop();
      for (int ii = 0; ii < 4; ii++) {
		int nx = i + dx[ii], ny = j + dy[ii];
		if (nx < 0 || ny < 0 || nx >= n || ny >= m)continue;
		if (c[nx][ny] == c[0][0]) {
			if (!fc[nx][ny]) {
              q.push({nx, ny});
              vis[nx][ny] = fc[nx][ny] = true;
            }
		} else if (!vis[nx][ny]) {
			if (c[nx][ny] == 'F')f.pb({nx, ny});
			else if (c[nx][ny] == 'R')r.pb({nx, ny});
			vis[nx][ny] = true;
		}
	}
    }
}

int main () {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n >> m;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cin >> c[i][j];
		}
	}
	dfs(0, 0);
	char cur = 'R';
	if (c[0][0] == cur)cur = 'F';
	while (!f.empty() || !r.empty()) {
		if (cur == 'R') {
			if (!r.empty())ans++;
			while (!r.empty()) {
				int x = r.back().F, y = r.back().S;
				r.pop_back();
				for (int i = 0; i < 4; i++) {
					int nx = x + dx[i], ny = y + dy[i];
					if (nx < 0 || ny < 0 || nx >= n || ny >= m)continue;
					if (vis[nx][ny])continue;
					vis[nx][ny] = true;
					if (c[nx][ny] == 'R')r.pb({nx, ny});
					else if (c[nx][ny] == 'F')f.pb({nx, ny});
				}
			}
		} else {
			if (!f.empty()) {
				ans++;
			}
			while (!f.empty()) {
				int x = f.back().F, y = f.back().S;
				f.pop_back();
				for (int i = 0; i < 4; i++) {
					int nx = x + dx[i], ny = y + dy[i];
					if (nx < 0 || ny < 0 || nx >= n || ny >= m)continue;
					if (vis[nx][ny])continue;
					vis[nx][ny] = true;
					if (c[nx][ny] == 'R')r.pb({nx, ny});
					else if (c[nx][ny] == 'F')f.pb({nx, ny});
				}
			}
		}
		if (cur == 'F')cur = 'R';
		else cur = 'F';
	}
	cout << ans;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 9564 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 6748 KB Output is correct
4 Correct 6 ms 9952 KB Output is correct
5 Correct 2 ms 6744 KB Output is correct
6 Correct 1 ms 4444 KB Output is correct
7 Correct 1 ms 6796 KB Output is correct
8 Correct 1 ms 6744 KB Output is correct
9 Correct 1 ms 4956 KB Output is correct
10 Correct 2 ms 5592 KB Output is correct
11 Correct 2 ms 6748 KB Output is correct
12 Correct 4 ms 5980 KB Output is correct
13 Correct 2 ms 6748 KB Output is correct
14 Correct 2 ms 6748 KB Output is correct
15 Correct 9 ms 9696 KB Output is correct
16 Correct 11 ms 9564 KB Output is correct
17 Correct 9 ms 9432 KB Output is correct
18 Correct 8 ms 9820 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 46172 KB Output is correct
2 Correct 35 ms 17500 KB Output is correct
3 Correct 225 ms 47420 KB Output is correct
4 Correct 57 ms 24404 KB Output is correct
5 Correct 157 ms 37972 KB Output is correct
6 Correct 476 ms 71788 KB Output is correct
7 Correct 11 ms 47192 KB Output is correct
8 Correct 10 ms 46172 KB Output is correct
9 Correct 2 ms 4444 KB Output is correct
10 Correct 1 ms 4444 KB Output is correct
11 Correct 11 ms 46940 KB Output is correct
12 Correct 2 ms 6748 KB Output is correct
13 Correct 43 ms 17584 KB Output is correct
14 Correct 21 ms 13404 KB Output is correct
15 Correct 17 ms 15708 KB Output is correct
16 Correct 21 ms 7260 KB Output is correct
17 Correct 88 ms 27608 KB Output is correct
18 Correct 60 ms 25972 KB Output is correct
19 Correct 59 ms 24544 KB Output is correct
20 Correct 70 ms 24916 KB Output is correct
21 Correct 137 ms 40528 KB Output is correct
22 Correct 172 ms 38088 KB Output is correct
23 Correct 163 ms 31956 KB Output is correct
24 Correct 175 ms 40388 KB Output is correct
25 Correct 285 ms 47300 KB Output is correct
26 Correct 336 ms 94296 KB Output is correct
27 Correct 441 ms 73936 KB Output is correct
28 Correct 468 ms 71596 KB Output is correct
29 Correct 470 ms 68404 KB Output is correct
30 Correct 471 ms 76836 KB Output is correct
31 Correct 322 ms 43980 KB Output is correct
32 Correct 360 ms 64956 KB Output is correct