HDU 1253 三维搜索bfs

也是以前做的一个题,当时不会。

bfs:

#include<stdio.h>
#include<string.h>
int a,b,c;
int vis[55][55][55],map[55][55][55];

int dx[6]={0,0,0,0,-1,1};
int dy[6]={0,0,1,-1,0,0};
int dz[6]={1,-1,0,0,0,0};
struct node
{
    int x,y,z;
    int time1;
}pos,npos,queue[55*55*55];

int bfs()
{
     int front=0,rear=0,d;
     pos.x=0; pos.y=0; pos.z=0; pos.time1=0;
     vis[0][0][0]=1;
     queue[rear++]=pos;

     while(rear>front)
     {
         pos=queue[front++];
         if(pos.x==a-1&&pos.y==b-1&&pos.z==c-1)
         return pos.time1;

        for(d=0; d<6; d++)
        {
            npos.x=pos.x+dx[d]; npos.y=pos.y+dy[d]; npos.z=pos.z+dz[d]; npos.time1=pos.time1+1;
            if(npos.x>=0&&npos.x<a&&npos.y>=0&&npos.y<b&&npos.z>=0&&npos.z<c
               &&!vis[npos.x][npos.y][npos.z]&&!map[npos.x][npos.y][npos.z])
            {
                vis[npos.x][npos.y][npos.z]=1;
                queue[rear++]=npos;
            }
        }
     }
     return -1;
};

int main()
{
    int t,i,j,k,time2,time;
    scanf("%d",&t);
    while(t--)
    {
        memset(vis,0,sizeof(vis));
        scanf("%d%d%d%d",&a,&b,&c,&time2);
        for(k=0; k<a; k++)
        for(i=0; i<b; i++)
        for(j=0; j<c; j++)
        scanf("%d",&map[k][i][j]);
        time=bfs();

        if(time<=time2&&time!=-1)
        printf("%d\n",time);
        else
        printf("-1\n");
    }
}