Submission #862587

#	Time	Username	Problem	Language	Result	Execution time	Memory
862587		neodoomer	Tracks in the Snow (BOI13_tracks)	C++14	0 / 100	1397 ms	1048576 KiB

tracks

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define F first
#define S second
#define pi pair<int,int>

int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n,m;
    cin>>n>>m;
    char g[n][m];
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            cin>>g[i][j];
        }
    }
    vector<pair<pi,bool> > adj[n][m];
    int vis[n][m];
    memset(vis,-1,sizeof vis);
    int dx[]={0,0,-1,1};
    int dy[]={-1,1,0,0};
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            for(int d=0;d<4;d++)
            {
                int ni=i+dx[d],nj=j+dy[d];
                if(ni<n && ni>=0 && nj<m && nj>=0 && g[i][j]!='.' && g[ni][nj]!='.'){
                    adj[i][j].pb({{ni,nj},(g[i][j]==g[ni][nj])});
                }
            }
        }
    }
    deque<pi> dq;
    dq.pb({0,0});vis[0][0]=0;
    int ans=0;
    while(!dq.empty()){
        int i=dq.front().F,j=dq.front().S;
        dq.pop_back();
        for(auto p:adj[i][j])
        {
            int ni=p.F.F,nj=p.F.S,w=p.S;
            if(vis[ni][nj]!=-1)continue;
            vis[ni][nj]=w+vis[i][j];
            ans=max(ans,vis[ni][nj]);
            if(w)dq.pb({ni,nj});
            else dq.push_front({ni,nj});
        }
    }
    cout<<ans;

    return 0;
}

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