Submission #10018399

---

Source Code Expand

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

/* 幅優先探索。dequeをキューとして使う。ABC007/c とほぼ同じ。スタート地点が複数あるので、最初の時点でキューに複数のタプルが挿入される。*/
int main(void){
    int H,W;
    cin >> H >> W;
    char board[H][W];
    deque<tuple<int, int, int>> will_search;
    int dot_count = 0;
    rep(i,H){
        rep(j,W){
            cin >> board[i][j];
            if(board[i][j] == '#')will_search.emplace_back(make_tuple(i,j,0));
        }
    }
    const int DIRECTION_NUM = 4;
    const int dx[DIRECTION_NUM] = {1, -1, 0, 0};
    const int dy[DIRECTION_NUM] = {0, 0, 1, -1};
    int ans = 0;
    while(!will_search.empty()){
        tuple<int, int, int> current_location = will_search.front();
        will_search.pop_front();
        rep(i,DIRECTION_NUM){
            int next_y = get<0>(current_location) + dy[i];
            int next_x = get<1>(current_location) + dx[i];
            int step = get<2>(current_location) + 1;
            if(next_x >= 0 && next_x < W && next_y >= 0 && next_y < H){
                if(board[next_y][next_x] == '.'){
                    will_search.emplace_back(make_tuple(next_y, next_x, step));
                    board[next_y][next_x] = '#';
                    ans = step;
                }
            }
        }
    }
    cout << ans << endl;
    return 0;
}

Submission Info

Judge Result