Submission #1313802

#	Time	Username	Problem	Language	Result	Execution time	Memory
1313802		Nipphitch	Tracks in the Snow (BOI13_tracks)	C++20	100 / 100	434 ms	119208 KiB

tracks

#include <bits/stdc++.h>
using namespace std;
const int N=4005;
const int dy[]={-1,1,0,0};
const int dx[]={0,0,-1,1};

int n,m,d[N][N],ans;
char c[N][N];
deque <pair <int,int>> q;

bool inside(int y,int x){
    if(y<1 || y>n || x<1 || x>m) return false;
    else return true;
}

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m;
    for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) cin >> c[i][j];
    d[1][1]=1;
    q.push_back({1,1});
    while(!q.empty()){
        auto [y,x]=q.front();
        q.pop_front();
        ans=max(ans,d[y][x]);
        for(int i=0;i<4;i++){
            int yy=y+dy[i],xx=x+dx[i];
            if(!inside(yy,xx) || d[yy][xx]!=0 || c[yy][xx]=='.') continue;
            if(c[yy][xx]==c[y][x]){
                d[yy][xx]=d[y][x];
                q.push_front({yy,xx});
            }
            else{
                d[yy][xx]=d[y][x]+1;
                q.push_back({yy,xx});
            }
        }
    }
    cout << ans;
}

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