백준 14716번 현수막 C++

출처 : https://www.acmicpc.net/problem/14716

 

대각선까지 고려하는 bfs, dfs 탐색 문제이다.

 

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <algorithm>
#include <utility>
#include <stack>
#include <queue>
#include <math.h>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>

using namespace std;
typedef long long ll;

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	int m, n;
	cin >> m >> n;

	int posR[8] = { -1,-1,0,1,1,1,0,-1 };
	int posC[8] = { 0,1,1,1,0,-1,-1,-1 };

	vector<vector<int>> v(m, vector<int>(n));
	for (int i = 0; i < m; i++) {
		for (int j = 0; j < n; j++) {
			cin >> v[i][j];
		}
	}
	int cnt = 0;
	queue<pair<int, int>> q;
	for (int i = 0; i < m; i++) {
		for (int j = 0; j < n; j++) {
			if (v[i][j] == 1) {
				cnt++;
				q.push({ i,j });
				v[i][j] = 0;
				while (!q.empty()) {
					auto a = q.front();
					q.pop();
					for (int k = 0; k < 8; k++) {
						int nextRow = a.first + posR[k];
						int nextCol = a.second + posC[k];
						if (nextRow < 0 || nextRow >= m) continue;
						if (nextCol < 0 || nextCol >= n) continue;
						if (v[nextRow][nextCol] == 0) continue;
						q.push({ nextRow,nextCol });
						v[nextRow][nextCol] = 0;
					}
				}
			}
		}
	}
	cout << cnt;
};