[BOJ] 7576 토마토 (G4)

Author: uiop5809

박예진/9주차/260223.cpp

@@ -0,0 +1,70 @@
+//https://www.acmicpc.net/problem/7576
+#include <iostream>
+#include <vector>
+#include <queue>
+using namespace std;
+
+struct Node {
+    int x, y;
+};
+
+int M, N, answer;
+int arr[1001][1001];
+bool visited[1001][1001];
+
+const int dx[4] = {-1, 0, 1, 0};
+const int dy[4] = {0, 1, 0, -1};
+
+queue<pair<Node, int>> q;
+
+bool OOB(int x, int y) {
+    return x < 0 || x >= N || y < 0 || y >= M;
+}
+
+void bfs() {
+    while(!q.empty()) {
+        pair<Node, int> now = q.front();
+        q.pop();
+
+        answer = max(answer, now.second);
+
+        for(int dir = 0; dir < 4; dir++){
+            int nx = now.first.x + dx[dir];
+            int ny = now.first.y + dy[dir];
+
+            if (OOB(nx, ny) || visited[nx][ny] || arr[nx][ny] == -1) continue; 
+
+            visited[nx][ny] = true;
+            q.push({{nx, ny}, now.second + 1});
+        }
+    }
+}
+
+int main(){
+    ios::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    cin >> M >> N;
+    for(int i = 0; i < N; i++){
+        for(int j = 0; j < M; j++){
+            cin >> arr[i][j];
+            if (arr[i][j] == 1) {
+                q.push({{i, j}, 0});
+                visited[i][j] = true;
+            }
+        }
+    }
+    bfs();
+  
+    // 만약에 방문 안 한 곳
+    for(int i = 0; i < N; i++){
+        for(int j = 0; j < M; j++){
+            if (!visited[i][j] && arr[i][j] != -1) {
+                cout << -1;
+                return 0;
+            }
+        }
+    }
+    cout << answer;
+    return 0;
+}