Submission #2554764

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0;i<(int)(n);i++)
typedef pair<int,int> pii;

const int h = 19, w = 15;
char mp[20][20];
int n;
int bpos[20];

unordered_map<int,int> dist[1<<20];

int dx[] = {1,0,-1,0,1,1,-1,-1};
int dy[] = {0,1,0,-1,1,-1,-1,1};

int main(){
  REP(i,h)scanf("%s",mp[i]);
  n = 0;
  int wpos = -1;
  REP(i,h)REP(j,w){
    if(mp[i][j]=='O'){
      wpos = (i<<5) + j;
    }else if(mp[i][j]=='X'){
      bpos[n++] = (i<<5) + j;
    }
  }
  queue<int> Q;
  dist[0][wpos] = 0;
  Q.push((0<<10) + wpos);
  while(!Q.empty()){
    int mask = Q.front() >> 10;
    int pos = Q.front() & 1023;
    Q.pop();
    int wy = pos>>5;
    int wx = pos&31;
    // printf("%d, %d, %d\n", wy, wx, mask);
    int dst = dist[mask][pos];
    // 8 way
    REP(d,8){
      int cy = wy, cx = wx;
      int add = 0;
      while(true){
        int ny = cy + dy[d], nx = cx + dx[d];
        int pp = (ny<<5) + nx;
        if(nx<0 || ny<0 || nx>=w || ny>=h){
          cy = ny;
          cx = nx;
          break;
        }
        // exist check
        bool ok = false;
        REP(i,n)if(bpos[i]==pp && ((mask>>i)&1)==0){
          ok = true;
          add |= (1<<i);
          break;
        }
        cy = ny;
        cx = nx;
        if(!ok)break;
      }
      if(add==0)continue;
      if((cy>h-1) || (cy==h-1 && (0<=cy || cy<w))){
        // goal
        printf("%d\n",dst+1);
        return 0;
      }
      if(cy<0 || cx<0 || cx>=w)continue;
      int nmsk = mask | add;
      int pos = (cy<<5) | cx;
      if(dist[nmsk].count(pos)==0){
        dist[nmsk][pos] = dst+1;
        Q.push((nmsk<<10) + pos);
      }
    }
  }
  puts("-1");
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:17:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   REP(i,h)scanf("%s",mp[i]);
                            ^

Judge Result