Submission #1302631

#	Time	Username	Problem	Language	Result	Execution time	Memory
1302631		lunarecho	Tracks in the Snow (BOI13_tracks)	C++20	2.19 / 100	391 ms	18440 KiB

tracks

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

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

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, m;
    cin>>n>>m;
    vector<vector<char>> grid(n, vector<char>(m));
    for(int i=0;i<n;++i) {
        for(int j=0;j<m;++j) {
            cin>>grid[i][j];
        }
    }
    vector<vector<bool>> vis(n, vector<bool>(m, false));
    int ans = 0;
    for(int i=0;i<n;++i) {
        for(int j=0;j<m;++j) {
            if(!vis[i][j] && grid[i][j] != '.') {
                queue<pair<int, int>> q;
                bool f = grid[i][j] == 'F', s = !f;
                q.push({i, j});
                vis[i][j] = true;
                while(!q.empty()) {
                    auto it = q.front();
                    q.pop();
                    for(int k=0;k<4;++k) {
                        int x = it.first + dx[k], y = it.second + dy[k];
                        if(x >= 0 && x < n && y >= 0 && y < m && 
                            !vis[x][y] && grid[x][y] != '.') {
                            q.push({x, y});
                            vis[x][y] = true;
                            if(grid[x][y] == 'F') {
                                f = true;
                            } else {
                                s = true;
                            }
                        } 
                    }
                }
                if(f && s) {
                    ans += 2;
                } else {
                    ++ans;
                }
            }
        }
    }
    cout<<ans<<'\n';

    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 2.1875 / 70