백준 1303번 전쟁-전투 C++

출처 : https://www.acmicpc.net/problem/1303

간단한 bfs 응용문제이다.

코드에 전혀 문제가 없는데 통과가 안돼서 계속 고민하다가 문제를 다시 읽어봤는데 가로와 세로를 거꾸로 입력받았었다. 역시 문제는 꼼꼼히 읽어야 한다.

 

#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 n, m;
int posR[4] = { -1,0,1,0 };
int posC[4] = { 0,1,0,-1 };

int bfs(char c, int row, int col, const vector<vector<char>> &v, vector<vector<bool>> &visited) {
	queue<pair<int, int>> q;
	visited[row][col] = true;
	q.push({ row,col });
	int cnt = 1;
	while (!q.empty()) {
		auto a = q.front();
		q.pop();
		for (int i = 0; i < 4; i++) {
			int nextRow = a.first + posR[i];
			int nextCol = a.second + posC[i];
			if (nextRow < 0 || nextRow >= n) continue;
			if (nextCol < 0 || nextCol >= m) continue;
			if (visited[nextRow][nextCol]) continue;
			if (v[nextRow][nextCol] != c) continue;
			visited[nextRow][nextCol] = true;
			q.push({ nextRow,nextCol });
			cnt++;
		}
	}
	return cnt * cnt;
}

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

	cin >> m >> n;
	vector<vector<char>> v(n, vector<char>(m));
	vector<vector<bool>> visited(n, vector<bool>(m, false));
	string str;
	for (int i = 0; i < n; i++) {
		cin >> str;
		for (int j = 0; j < m; j++) {
			v[i][j] = str[j];
		}
	}
	int ans1 = 0;
	int ans2 = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if (!visited[i][j]) {
				if (v[i][j] == 'W') {
					ans1 += bfs('W', i, j, v, visited);
				}
				else {
					ans2 += bfs('B', i, j, v, visited);
				}
			}
		}
	}
	cout << ans1 << " " << ans2;
};