#include using namespace std; char board[1001][1001]; int isVisit[1001][1001]; int isVisitFire[1001][1001]; int main(){ cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(false); int R, C; cin >> R >> C; queue> fireQ; queue> jihoonQ; for(int i = 0; i < R; i++){ string input; cin >> input; for(int j = 0; j < C; j++){ board[i][j] = input[j]; isVisit[i][j] = -1; isVisitFire[i][j] = -1; if(board[i][j] == 'F'){ fireQ.push(make_pair(i, j)); isVisitFire[i][j] = 0; }else if(board[i][j] == 'J'){ jihoonQ.push(make_pair(i, j)); isVisit[i][j] = 0; } } } while(!fireQ.empty()){ int curX = fireQ.front().first; int curY = fireQ.front().second; fireQ.pop(); int dx[4] = {0, 1, 0, -1}; int dy[4] = {1, 0, -1, 0}; for(int i = 0; i < 4; i++){ int newX = curX + dx[i]; int newY = curY + dy[i]; if(newX < 0 || newX >= R || newY < 0 || newY >= C){ continue; } if(isVisitFire[newX][newY] >= 0 || board[newX][newY] == '#'){ continue; } fireQ.push(make_pair(newX, newY)); isVisitFire[newX][newY] = isVisitFire[curX][curY] + 1; } } while(!jihoonQ.empty()){ int curX = jihoonQ.front().first; int curY = jihoonQ.front().second; jihoonQ.pop(); int dx[4] = {0, 1, 0, -1}; int dy[4] = {1, 0, -1, 0}; for(int i = 0; i < 4; i++){ int newX = curX + dx[i]; int newY = curY + dy[i]; if(newX < 0 || newX >= R || newY < 0 || newY >= C){ cout << isVisit[curX][curY] + 1 << "\n"; return 0; } if(isVisit[newX][newY] >= 0 || board[newX][newY] == '#'){ continue; } if(isVisitFire[newX][newY] >= 0 && isVisitFire[newX][newY] <= isVisit[curX][curY] + 1){ continue; } jihoonQ.push(make_pair(newX, newY)); isVisit[newX][newY] = isVisit[curX][curY] + 1; } } cout << "IMPOSSIBLE" << "\n"; return 0; }

4179. 불!

4179. 불!