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Submission #798327

# Submission time Handle Problem Language Result Execution time Memory
798327 2023-07-30T15:24:12 Z arijit_biswas Tracks in the Snow (BOI13_tracks) C++17
100 / 100
 600 ms 110808 KB 
#include <bits/stdc++.h>
#define fast ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
using namespace std;

// void setIO(string filename) {
//     freopen((filename + ".in").c_str(), "r", stdin);
//     freopen((filename + ".out").c_str(), "w", stdout);
// }

int n, m;
vector<vector<char>> snow;
vector<vector<int>> dis;
int ans;

int dx[] = {0, 1, 0, -1};
int dy[] = {1, 0, -1, 0};

bool check(int x, int y) {
    return (x >= 0 && x < n && y >= 0 && y < m && snow[x][y] != '.');
}

void bfs(pair<int, int> st) {
    dis.assign(n, vector<int>(m, 1e9));
    deque<pair<int, int>> dq;
    dis[st.first][st.second] = 0;
    dq.push_back({st.first, st.second});
    while (!dq.empty()) {
        auto node = dq.front(); dq.pop_front();
        int i = node.first, j = node.second;
        ans = max(ans, dis[i][j]);
        for (int k = 0; k < 4; k++) {
            int x = i + dx[k], y = j + dy[k];
            if (check(x, y) && dis[x][y] == 1e9) {
                if (snow[x][y] == snow[i][j]) {
                    // 0 edge
                    dis[x][y] = dis[i][j];
                    dq.push_front({x, y});
                } else {
                    // 1 edge
                    dis[x][y] = dis[i][j] + 1;
                    dq.push_back({x, y});
                }
            }
        }
    }
}

void solution() {
    cin >> n >> m;
    snow.resize(n, vector<char>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cin >> snow[i][j];
        }
    }
    bfs({0, 0});
    cout << ans + 1 << endl;
}

int main() {
    // setIO("");
    fast;
    solution();
    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 1620 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 5 ms 1416 KB Output is correct
5 Correct 2 ms 724 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 0 ms 324 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 328 KB Output is correct
10 Correct 2 ms 596 KB Output is correct
11 Correct 2 ms 596 KB Output is correct
12 Correct 4 ms 852 KB Output is correct
13 Correct 2 ms 724 KB Output is correct
14 Correct 2 ms 724 KB Output is correct
15 Correct 9 ms 1620 KB Output is correct
16 Correct 10 ms 1608 KB Output is correct
17 Correct 7 ms 1620 KB Output is correct
18 Correct 5 ms 1364 KB Output is correct

Subtask #2
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 852 KB Output is correct
2 Correct 38 ms 8180 KB Output is correct
3 Correct 261 ms 79036 KB Output is correct
4 Correct 73 ms 18896 KB Output is correct
5 Correct 168 ms 44620 KB Output is correct
6 Correct 597 ms 93500 KB Output is correct
7 Correct 2 ms 852 KB Output is correct
8 Correct 2 ms 852 KB Output is correct
9 Correct 2 ms 596 KB Output is correct
10 Correct 1 ms 520 KB Output is correct
11 Correct 2 ms 852 KB Output is correct
12 Correct 1 ms 460 KB Output is correct
13 Correct 37 ms 8160 KB Output is correct
14 Correct 22 ms 4820 KB Output is correct
15 Correct 17 ms 5412 KB Output is correct
16 Correct 18 ms 3524 KB Output is correct
17 Correct 104 ms 20456 KB Output is correct
18 Correct 79 ms 20040 KB Output is correct
19 Correct 68 ms 18884 KB Output is correct
20 Correct 60 ms 17356 KB Output is correct
21 Correct 155 ms 46152 KB Output is correct
22 Correct 170 ms 44684 KB Output is correct
23 Correct 206 ms 38480 KB Output is correct
24 Correct 152 ms 45124 KB Output is correct
25 Correct 443 ms 78964 KB Output is correct
26 Correct 574 ms 110808 KB Output is correct
27 Correct 538 ms 104620 KB Output is correct
28 Correct 600 ms 93480 KB Output is correct
29 Correct 593 ms 90688 KB Output is correct
30 Correct 565 ms 96052 KB Output is correct
31 Correct 417 ms 51232 KB Output is correct
32 Correct 577 ms 103080 KB Output is correct