PAT (Advanced Level) 1091. Acute Stroke (30)

BFS求连通块。递归会爆栈。

#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<map>
#include<queue>
#include<stack>
#include<vector>
using namespace std;

int M,N,L,T;
int A[][][];
bool f[][][];

int dir[][]={
    {,,},
    {,,-},
    {,,},
    {,-,},
    {,,},
    {-,,}
};

struct Point
{
    int a,b,c;
    Point (int aa,int bb,int cc)
    {
        a=aa; b=bb; c=cc;
    }
};

int Find(int a,int b,int c)
{
    int res=;
    queue<Point>q;

    Point p(a,b,c);
    q.push(p);
    f[a][b][c]=;

    while(!q.empty())
    {
        res++;
        Point head=q.front(); q.pop();
        for(int i=;i<;i++)
        {
            int na=head.a+dir[i][];
            int nb=head.b+dir[i][];
            int nc=head.c+dir[i][];

            if(na>L||na<) continue;
            if(nb>M||nb<) continue;
            if(nc>N||nc<) continue;

            if(A[na][nb][nc]==) continue;
            if(f[na][nb][nc]==) continue;

            Point p(na,nb,nc);
            q.push(p);
            f[na][nb][nc]=;
        }
    }
    return res;
}

int main()
{
    memset(A,,sizeof A);
    memset(f,,sizeof f);
    scanf("%d%d%d%d",&M,&N,&L,&T);
    for(int k=;k<=L;k++)
        for(int i=;i<=M;i++)
            for(int j=;j<=N;j++)
                scanf("%d",&A[k][i][j]);
    int sum=;
    for(int k=;k<=L;k++)
        for(int i=;i<=M;i++)
            for(int j=;j<=N;j++)
            {
                if(A[k][i][j]==) continue;
                if(f[k][i][j]==) continue;
                int res=Find(k,i,j);
                if(res>=T) sum=sum+res;
            }
    printf("%d\n",sum);

    return ;
}