Submission #1306785

#	Time	Username	Problem	Language	Result	Execution time	Memory
1306785		denchik_23	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	637 ms	120040 KiB

tracks

#include <bits/stdc++.h>
using namespace std;

int n, m;
vector<string> meadow;
int dx[4]{1, -1, 0, 0}, dy[4]{0, 0, 1, -1};

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

int main() {
    cin >> n >> m;
    meadow.resize(n);
    for (int i = 0; i < n; i++) cin >> meadow[i];

    int ans = 1;
    vector<vector<int>> dist(n, vector<int>(m));

    deque<pair<int, int>> q;
    q.push_back({0, 0});
    dist[0][0] = 1;
    while (!q.empty()) {
        pair<int, int> c = q.front();
        q.pop_front();
        ans = max(ans, dist[c.first][c.second]);

        for (int i = 0; i < 4; i++) {
            int x = c.first + dx[i], y = c.second + dy[i];
            if (check(x, y) && dist[x][y] == 0) {
                if (meadow[x][y] == meadow[c.first][c.second]) {
                    dist[x][y] = dist[c.first][c.second];
                    q.push_front({x, y});
                }else {
                    dist[x][y] = dist[c.first][c.second] + 1;
                    q.push_back({x, y});
                }
            }
        }
    }
    cout << ans << endl;
    return 0;
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70