[5427] 불

내 코드

#include <iostream>
#include <queue>
#include <utility>
#include <algorithm>
using namespace std;

char field[1000][1000];
int fdis[1000][1000];
int sdis[1000][1000];
int t,m,n;
int xdis[4] = {1,0,-1,0};
int ydis[4] = {0,1,0,-1};
int main(void)
{
    cin >> t;
    while(t--)
    {
        bool ispossible = false;
        queue<pair<int,int>> f;
        queue<pair<int,int>> s;
        cin >> m >> n;
        for(int i = 0;i<n;i++)
        {
            fill(fdis[i],fdis[i]+m,-1);
            fill(sdis[i],sdis[i]+m,-1);
        }
        for(int i =0;i<n;i++)
        {
            for(int j =0;j<m;j++)
            {
                cin >> field[i][j];
                if(field[i][j] == '@')
                {
                    sdis[i][j] = 0;
                    s.push({i,j});
                }
                else if(field[i][j] == '*')
                {
                    fdis[i][j] = 0;
                    f.push({i,j});
                }
            }
        }
        while(!f.empty())
        {
            pair<int,int> cur = f.front(); f.pop();
            for(int i = 0;i<4;i++)
            {
                int curx = cur.first + xdis[i];
                int cury = cur.second + ydis[i];
                if(curx<0||curx>=n||cury<0||cury>=m) continue;
                if(fdis[curx][cury] >= 0 || field[curx][cury] == '#') continue;
                f.push({curx,cury});
                fdis[curx][cury] = fdis[cur.first][cur.second] + 1;
            }
        }
        while(!s.empty())
        {
            pair<int,int> cur = s.front(); s.pop();
            for(int i = 0;i<4;i++)
            {
                int curx = cur.first + xdis[i];
                int cury = cur.second + ydis[i];
                if(curx<0||curx>=n||cury<0||cury>=m)
                {
                    cout << sdis[cur.first][cur.second] + 1 << '\n';
                    while(!s.empty())
                        s.pop();
                    ispossible = true;
                    break;
                }
                if(sdis[curx][cury] >= 0 || field[curx][cury] != '.') continue;
                if((sdis[cur.first][cur.second] + 1 >= fdis[curx][cury]) && fdis[curx][cury] >=0) continue;
                    sdis[curx][cury] = sdis[cur.first][cur.second] + 1;
                    s.push({curx,cury});
            }
        }
        if(!ispossible)
        cout << "IMPOSSIBLE" << '\n';
    }
        
}

정답

#include <bits/stdc++.h>
using namespace std;
#define X first
#define Y second
int TC, bX, bY;
int board[1002][1002];
int visF[1002][1002];
int visS[1002][1002];
int dx[4] = {0, 0, 1, -1};
int dy[4] = {1, -1, 0, 0};
int main(void) {
  ios::sync_with_stdio(0);
  cin.tie(0);

  cin >> TC;
  for (int testNo = 0; testNo < TC; testNo++) {
    bool escape = false;
    queue<pair<int, int>> Qf = {}, Qs = {};
    cin >> bY >> bX;
    for (int i = 0; i < bX; i++) {
      fill(visF[i], visF[i] + bY, 0);
      fill(visS[i], visS[i] + bY, 0);
    }
    for (int i = 0; i < bX; i++)
      for (int j = 0; j < bY; j++) {
        char c;
        cin >> c;
        if (c == '#') board[i][j] = -1;
        else {
          if (c == '@') {
            Qs.push({i, j});
            visS[i][j] = 1;
          } 
          else if (c == '*') {
            Qf.push({i, j});
            visF[i][j] = 1;
          }
          board[i][j] = 0;
        }
      }
    while (!Qf.empty()) {
      auto v = Qf.front();
      Qf.pop();
      for (int k = 0; k < 4; k++) {
        int nx = v.X + dx[k];
        int ny = v.Y + dy[k];
        if (nx < 0 || bX <= nx || ny < 0 || bY <= ny) continue;
        if (board[nx][ny] == -1) continue;
        if (visF[nx][ny]) continue;
        visF[nx][ny] = visF[v.X][v.Y] + 1;
        Qf.push({nx, ny});
      }
    }
    while ((!Qs.empty()) && (!escape)) {
      auto v = Qs.front();
      Qs.pop();
      for (int k = 0; k < 4; k++) {
        int nx = v.X + dx[k];
        int ny = v.Y + dy[k];
        if (nx < 0 || bX <= nx || ny < 0 || bY <= ny) {
          cout << visS[v.X][v.Y] << '\n';
          escape = true;
          break;
        }
        if (board[nx][ny] == -1) continue;
        if (visS[nx][ny]) continue;
        if (visF[nx][ny] != 0 && visF[nx][ny] <= visS[v.X][v.Y] + 1) continue;
        visS[nx][ny] = visS[v.X][v.Y] + 1;
        Qs.push({nx, ny});
      }
    }
    if (!escape) cout << "IMPOSSIBLE" << '\n';
  }
}