L3-004 tumor diagnosis (30 points) (3D BFS)

#include <bits/stdc++.h>
using namespace std;
int n, m, l, t;
const int N = 1300, M = 150, H = 70;
int arr[N][M][H], vis[N][M][H];
struct node
{
    
    int x, y, z;
};
int dx[] = {
    0, 0, 0, 0, 1, -1};
int dy[] = {
    0, 0, 1, -1, 0, 0};
int dz[] = {
    1, -1, 0, 0, 0, 0};
int dfs(int x, int y, int z)
{
    
    int ans = 0;
    queue<node> q;
    q.push({
    x, y, z});
    vis[x][y][z]=1;
    while (q.size())
    {
    
        auto p = q.front();
        q.pop();
        ans++;
        for (int i = 0; i < 6; i++)
        {
    
            int nx = dx[i] + p.x, ny = dy[i] + p.y, nz = dz[i] + p.z;
            if (nx < 1 || nx > n || ny < 1 || ny > m || nz < 1 || nz > l)
                continue;
            if (arr[nx][ny][nz] == 0)
                continue;
            if(vis[nx][ny][nz])continue;
            vis[nx][ny][nz]=1;
            q.push({
    nx, ny, nz});
            
        }
    }
    if (ans < t)
        ans = 0;
    return ans;
}
int main()
{
    
    cin >> n >> m >> l >> t;
    for (int k = 1; k <= l; k++)
        for (int i = 1; i <= n; i++)
        {
    
            for (int j = 1; j <= m; j++)
            {
    
                cin >> arr[i][j][k];
            }
        }
    int ans = 0;
    for (int k = 1; k <= l; k++)
        for (int i = 1; i <= n; i++)
        {
    
            for (int j = 1; j <= m; j++)
            {
    
                if (!vis[i][j][k] && arr[i][j][k])
                {
    
                    // cout<<i<<" "<<j<<" "<<k<<"\n";
                    // cout<<dfs(i,j,k)<<"\n";
                    ans += dfs(i, j, k);
                }
            }
        }
        cout<<ans<<"\n";
    return 0;
}