[BOJ] 2638 치즈 (G3)

Author: uiop5809

박예진/4주차/260123.cpp

@@ -0,0 +1,73 @@
+//https://www.acmicpc.net/problem/2638
+
+#include <iostream>
+#include <algorithm>
+#include <vector>
+#include <queue>
+using namespace std;
+
+int N, M, sum;
+int num[101][101];
+int cnt[101][101];
+bool c[101][101];
+
+int dx[4] = { 1, 0, -1, 0 };
+int dy[4] = { 0, -1, 0, 1 };
+
+queue <pair <int, int>> q;
+
+void bfs() {
+	q.push({ 1, 1 });
+	c[1][1] = 1;
+
+	sum = 0;
+	while (!q.empty()) {
+		int x = q.front().first;
+		int y = q.front().second;
+		q.pop();
+
+		for (int i = 0; i < 4; i++) {
+			int nx = x + dx[i];
+			int ny = y + dy[i];
+
+			if (nx < 1 || nx > N || ny < 1 || ny > M)
+				continue;
+			if (num[nx][ny] == 0 && !c[nx][ny]) {
+				q.push({ nx, ny });
+				c[nx][ny] = 1;
+				sum++;
+			}
+			else if (num[nx][ny] == 1) {
+				cnt[nx][ny]++;
+
+				if (cnt[nx][ny] >= 2) {
+					num[nx][ny] = 0;
+					c[nx][ny] = 1;
+				}
+			}
+		}
+	}
+}
+
+int main() {
+	ios::sync_with_stdio(false);
+	cin.tie(NULL); cout.tie(NULL);
+
+	cin >> N >> M;
+	for (int i = 1; i <= N; i++) {
+		for (int j = 1; j <= M; j++) {
+			cin >> num[i][j];
+		}
+	}
+
+	int res = 0;
+	while (1) {
+		bfs();
+		res++;
+		memset(c, 0, sizeof(c));
+		memset(cnt, 0, sizeof(cnt));
+
+		if (sum == N * M - 1) break;
+	}
+	cout << res - 1;
+}