백준 2573 빙산(bfs)

https://www.acmicpc.net/problem/2573

2573번: 빙산

#include <iostream>
#include <queue>

using namespace std;
const int MAX = 300;
int graph[MAX][MAX];
bool visited[MAX][MAX];
int N, M;
int result;
int tmpGraph[MAX][MAX];
int block;
typedef struct
{
    int x, y;
} Dir;
Dir dirMove[4] = {{-1, 0}, {1, 0}, {0, 1}, {0, -1}};

bool allZero()
{
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < M; j++)
        {
            if (graph[i][j] != 0)
                return false;
        }
    }
    return true;
}

void meltingIceberg(int x, int y)
{
    int cnt = 0;
    for (int i = 0; i < 4; i++)
    {
        int nextX = x + dirMove[i].x;
        int nextY = y + dirMove[i].y;
        if (0 <= nextX && nextX < N && 0 <= nextY && nextY < M && graph[nextX][nextY] == 0)
            cnt++;
    }
    if (graph[x][y] - cnt >= 0)
        tmpGraph[x][y] = graph[x][y] - cnt;
    else
        tmpGraph[x][y] = 0;
}

void dfs(int x, int y)
{
    visited[x][y] = true;
    for (int i = 0; i < 4; i++)
    {
        int nextX = x + dirMove[i].x;
        int nextY = y + dirMove[i].y;
        if (0 <= nextX && nextX < N && 0 <= nextY && nextY < M && !visited[nextX][nextY] && graph[nextX][nextY] != 0)
            dfs(nextX, nextY);
    }
}

void bfs(int x, int y)
{
    queue<pair<int, int>> q;
    q.push(make_pair(x, y));
    visited[x][y] = true;
    while (!q.empty())
    {
        int curX = q.front().first;
        int curY = q.front().second;
        q.pop();
        for (int i = 0; i < 4; i++)
        {
            int nextX = curX + dirMove[i].x;
            int nextY = curY + dirMove[i].y;
            if (0 <= nextX && nextX < N && 0 <= nextY && nextY < M && !visited[nextX][nextY] && graph[nextX][nextY] != 0)
            {
                visited[nextX][nextY] = true;
                q.push(make_pair(nextX, nextY));
            }
        }
    }
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> N >> M;
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < M; j++)
        {
            cin >> graph[i][j];
        }
    }
    while (1)
    {
        if (allZero())
        {
            cout << 0;
            return 0;
        }
        result++;

        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < M; j++)
            {
                meltingIceberg(i, j);
            }
        }

        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < M; j++)
            {
                graph[i][j] = tmpGraph[i][j];
            }
        }

        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < M; j++)
            {
                if (!visited[i][j] && graph[i][j] != 0)
                {
                    block++;
                    bfs(i, j);
                }
            }
        }

        if (block >= 2)
        {
            cout << result;
            break;
        }
        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < M; j++)
            {
                visited[i][j] = false;
            }
        }
        block = 0;
    }
}

어제 똑같은 코드였는데 노트북이 맛이 갔엇는지 아무 것도 출력이 되지 않아 무한루프에 빠진 줄 알았더니 아니었다....