Submission #270408

#	Time	Username	Problem	Language	Result	Execution time	Memory
270408		hieppgga	Portals (BOI14_portals)	C++14	0 / 100	1 ms	768 KiB

portals

#include<bits/stdc++.h>
#define fi first
#define se second
using namespace std;
void readInput()
{

}
void solve()
{

}
const int N=1004;
int m,n,d[N][N],lef[N][N],rig[N][N],up[N][N],down[N][N],dp[N][N];
char c[1004][1004];
int x[4]={1,-1,0,0};
int y[4]={0,0,1,-1};
int INF=1e7;
typedef pair<int,int> ii;
typedef pair<int,pair<int,int>> iii;
priority_queue<iii,vector<iii>,greater<iii>> pq;
queue<ii> q;
ii start,en;
void bfs()
{
    while(!q.empty())
    {
        ii u=q.front();
        q.pop();
        for(int i=0;i<4;i++)
        {
           if(u.fi+x[i]>=1&&u.fi+x[i]<=m&&u.se+y[i]>=1&&u.se+y[i]<=n&&d[u.fi+x[i]][u.se+y[i]]==m*n+1)
           {
               d[u.fi+x[i]][u.se+y[i]]=d[u.fi][u.se]+1;
               q.push({u.fi+x[i],u.se+y[i]});
           }
        }
    }
}
void dijkstra()
{
    for(int i=1;i<=m;i++)
       for(int j=1;j<=n;j++)
           dp[i][j]=INF;
    dp[start.fi][start.se]=0;
    pq.push({0,{start.fi,start.se}});
    while(!pq.empty())
    {
        iii u=pq.top();
        pq.pop();
        if(dp[u.se.fi][u.se.se]!=u.fi) continue;
        for(int i=0;i<4;i++)
        {
         if(u.se.fi+x[i]>=1&&u.se.fi+x[i]<=m&&u.se.se+y[i]>=1&&u.se.se+y[i]<=n&&dp[u.se.fi+x[i]][u.se.se+y[i]]>dp[u.se.fi][u.se.se]+1)
         {
             dp[u.se.fi+x[i]][u.se.se+y[i]]=dp[u.se.fi][u.se.se]+1;
             pq.push({ dp[u.se.fi+x[i]][u.se.se+y[i]],{u.se.fi+x[i],u.se.se+y[i]}});
         }
        }
        if(dp[up[u.se.fi][u.se.se]][u.se.se]>dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1)
        {
            dp[up[u.se.fi][u.se.se]][u.se.se]=dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1;
            pq.push({dp[up[u.se.fi][u.se.se]][u.se.se],{up[u.se.fi][u.se.se],u.se.se}});
        }
        if(dp[down[u.se.fi][u.se.se]][u.se.se]>dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1)
        {
            dp[down[u.se.fi][u.se.se]][u.se.se]=dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1;
            pq.push({dp[down[u.se.fi][u.se.se]][u.se.se],{down[u.se.fi][u.se.se],u.se.se}});
        }
        if(dp[u.se.fi][lef[u.se.fi][u.se.se]]>dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1)
        {
            dp[u.se.fi][lef[u.se.fi][u.se.se]]=dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1;
            pq.push({dp[u.se.fi][lef[u.se.fi][u.se.se]],{u.se.fi,lef[u.se.fi][u.se.se]}});
        }
         if(dp[u.se.fi][rig[u.se.fi][u.se.se]]>dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1)
        {
            dp[u.se.fi][rig[u.se.fi][u.se.se]]=dp[u.se.fi][u.se.se]+d[u.se.fi][u.se.se]+1;
            pq.push({dp[u.se.fi][rig[u.se.fi][u.se.se]],{u.se.fi,rig[u.se.fi][u.se.se]}});
        }
    }
}
int main()
{
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  readInput();
  solve();
  cin>>m>>n;
  for(int i=1;i<=m;i++)
    for(int j=1;j<=n;j++)
        d[i][j]=m*n+1;
  for(int i=1;i<=m;i++)
  {
      for(int j=1;j<=n;j++)
      {
          cin>>c[i][j];
          if(c[i][j]=='#')
          {
              q.push({i,j});
              d[i][j]=0;
              for(int k=0;k<4;k++)
              {
                  if(i+x[k]>=1&&i+x[k]<=m&&j+y[k]>=1&&j+y[k]<=n)
                     d[i+x[k]][j+y[k]]=0;
              }
          }
          else
          {
            if(c[i][j]=='S') start={i,j};
            if(c[i][j]=='C') en={i,j};
            if(i==1||i==m||j==1||j==n)
            {
                  q.push({i,j});
                  d[i][j]=0;
            }
          }
      }
  }
  bfs();
  for(int i=1;i<=m;i++)
  {
      int cnt=1;
      for(int j=1;j<=n;j++)
      {
          if(c[i][j]=='#') cnt=j+1;
          else
          lef[i][j]=cnt;
      }
      cnt=n;
      for(int j=n;j>=1;j--)
      {
          if(c[i][j]=='#') cnt=j-1;
          else
           rig[i][j]=cnt;
      }
  }
  for(int i=1;i<=n;i++)
  {
      int cnt=1;
      for(int j=1;j<=m;j++)
      {
          if(c[j][i]=='#') cnt=j+1;
          else up[j][i]=cnt;
      }
      cnt=m;
      for(int j=m;j>=1;j--)
      {
          if(c[j][i]=='#') cnt=j-1;
          else down[j][i]=cnt;
      }
  }
  dijkstra();
  cout<<dp[en.fi][en.se];

}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30