Submission #5263259

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Source Code Expand

#include<iostream>
#include<queue>
#include<map>

using namespace std;
int d[1001][1001];
int INF = 1e9;

int main(){
  queue<pair<int,pair<int, int> > > q;
  int H,W;
  cin >> H >> W;
  
  for (int i=0;i<H;i++){
  	for (int j=0;j<W;j++){
      d[i][j] = INF;
    }
  }
  string s;
  for(int i=0;i<H;i++){
    cin >> s;
    for(int j=0;j<W;j++){
      if(s[j] == '#'){
        d[i][j] = 0;
        q.push(make_pair(0,make_pair(i,j)));
      }
    }
  }
  while(!q.empty()){
    pair<int,pair<int, int> > a = q.front();
    q.pop();
    int dv = a.first;
    int x = a.second.first;
    int y = a.second.second;
    int dx = 1;
    int dy = 0;
    for (int j=0;j<4;j++){
      int t = dx;
      dx = dy;
      dy = -t;
      int xx = x + dx;
      int yy = y + dy;
      if (xx == -1 | xx == H){
        continue;
      }
      if (yy == -1 | yy == W){
        continue;
      }
      if (d[xx][yy] == INF){
        d[xx][yy] = dv + 1;
        q.push(make_pair(dv+1,make_pair(xx,yy)));
      }
    }
  }
  int ans = 0;
  for (int i=0;i<H;i++){
    for (int j=0;j<W;j++){
      if (ans < d[i][j]){
        ans = d[i][j];
      }
    }
  }
  cout << ans << endl;
}

Submission Info

Judge Result