백준 4963번 C++ 풀이

#include <iostream>
#include <algorithm>
#include <queue>
#include <climits>
#include <string>
#include <map>
using namespace std;

int buffer[51][51];
int delta[8][2] = { {1, 0}, {-1, 0}, {0, 1}, {0, -1},
                    {1, 1} ,{-1, -1}, {1, -1}, {-1,1} };

int main(){
    cin.tie(NULL);
    ios::sync_with_stdio(false);
    int n, m;
    cin >> n >> m;
    while ( !( n == 0 && m == 0 )){
        for (auto y = 0; y<m; y++){
            for (auto x=0; x<n; x++){
                cin >> buffer[x][y];
            }
        }
        int land = 0;
        for (auto y = 0; y<m; y++){
            for (auto x=0; x<n; x++){
                if (buffer[x][y] == 1){
                    land++;
                    buffer[x][y] = 0;
                    queue<pair<int, int>> q;

                    q.push(make_pair(x,y));

                    while (!q.empty()){
                        pair<int, int> top = q.front();
                        q.pop();
                        for (auto i=0; i<8; i++){
                            int nextX = top.first + delta[i][0];
                            int nextY = top.second + delta[i][1];

                            if ( 0 <= nextX && nextX < n &&
                               0 <= nextY && nextY <m ){
                                if (buffer[nextX][nextY] == 1){
                                     buffer[nextX][nextY] = 0;
                                     q.push(make_pair(nextX, nextY));
                                }
                            }
                        }
                    }

                }
            }
        }
        cout << land << '\n';
        cin >> n >> m;

    }
    return 0;
}