Submission #731552

#	Time	Username	Problem	Language	Result	Execution time	Memory
731552		kirakaminski968	Tracks in the Snow (BOI13_tracks)	C++17	100 / 100	665 ms	139368 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
int dx[4] = {0,1,-1,0};
int dy[4] = {1,0,0,-1};
int dist[4000][4000];
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    int H,W; cin >> H >> W;
    vector<string> grid(H);
    for(int i = 0;i<H;++i) cin >> grid[i];
    deque<pair<int,int>> q; q.push_front({0,0});
    dist[0][0] = 1;
    int ans = 1;
    while(!q.empty()){
        int x = q.front().first, y = q.front().second; q.pop_front();
        ans = max(ans,dist[x][y]);
        for(int i = 0;i<4;++i){
            int nx = x+dx[i], ny = y+dy[i];
            if(nx < 0 || nx >= H || ny < 0 || ny >= W) continue;
            if(grid[nx][ny] == '.' || dist[nx][ny] != 0) continue;
            if(grid[nx][ny] == grid[x][y]){
                dist[nx][ny] = dist[x][y];
                q.push_front({nx,ny});
            }
            else{
                dist[nx][ny] = dist[x][y]+1;
                q.push_back({nx,ny});
            }
        }
    }
    cout << ans << "\n";
    return 0;
}

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