Submission #203433

#	Time	Username	Problem	Language	Result	Execution time	Memory
203433		mdn2002	Tracks in the Snow (BOI13_tracks)	C++14	19.79 / 100	1415 ms	132024 KiB

tracks

#include<bits/stdc++.h>
using namespace std;
char a[4050][4050];
int n,m,dis[4050][4050],xx[]={1,-1,0,0},yy[]={0,0,1,-1},ans;
int main()
{
    cin>>n>>m;
    for(int i=0; i<n; i++)cin>>a[i];
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)dis[i][j]=1e9;
    }
    deque<pair<int,int> >dq;
    dq.push_front({0,0});
    dis[0][0]=1;
    while(dq.size())
    {
        pair<int,int>pr=dq.front();
        dq.pop_front();
        int ox=pr.first,oy=pr.second;
        for(int i=0; i<4; i++)
        {
            int x=ox+xx[i],y=oy+yy[i];
            if(0<=x&&x<n&&0<=y&&y<m&&a[x][y]!='.')
            {
                int pls=0;
                if(a[ox][oy]!=a[x][y])pls++;
                if(dis[x][y]>dis[ox][oy]+pls)
                {
                    dis[x][y]=dis[ox][oy]+pls;
                    if(pls)dq.push_back({x,y});
                    else dq.push_front({x,y});
                }
            }
        }
    }
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)ans=max(ans,dis[i][j]);
    }
    cout<<ans;
}

• Subtask 1: 6.666666666666667 / 30
• Subtask 2: 13.125 / 70