Submission #1234445

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234445		ethan7sky	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	384 ms	111936 KiB

tracks

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

int dx[4]{1, -1, 0, 0}, dy[4]{0, 0, 1, -1};
bool inside(int x, int y, int h, int w) {
    return 0<=x&&x<h&&0<=y&&y<w;
}

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

    int h, w; cin >> h >> w;
    vector<string> a(h);
    for(string& s: a) cin >> s;

    vector<vector<int>> depth(h, vector<int>(w));
    int ans = 1;

    deque<pair<int, int>> dq;
    dq.push_back({0, 0});
    depth[0][0] = 1;

    while(dq.size()) {
        auto c = dq.front(); dq.pop_front();
        ans = max(ans, depth[c.first][c.second]);

        for(int i=0; i<4; i++){
            int x = c.first+dx[i]; int y = c.second + dy[i];
            if(inside(x, y, h, w) && a[x][y]!='.'&&depth[x][y]==0) {
                if(a[x][y]==a[c.first][c.second]) {
                    depth[x][y] = depth[c.first][c.second];
                    dq.push_front({x, y});
                } else {
                    depth[x][y] = depth[c.first][c.second]+1;
                    dq.push_back({x, y});
                }
                
            }
        }
    }
    cout << ans;
    
}

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