hdu1253 胜利大逃亡(三维bfs索搜)

http://acm.hdu.edu.cn/showproblem.php?pid=1253

第一次做做三维的，思路跟二维的没有区别。这道题目第一次出现Memory Limit Exceeded 这种问题，找了很长时间才发现应该是先判断在存入，可以省很多内存。

代码：

#include<iostream>
#include<queue>
using namespace std;
int s[51][51][51];
int vis[51][51][51];
int _move[6][3] = { { 0, 0, 1 }, { 0, 0, -1 }, { 1, 0, 0 }, { -1, 0, 0 }, { 0, 1, 0 }, {0,-1,0} };
int a, b, c, t, ok;
struct box
{
    int x, y, z,time;
};
int bian(int x, int y, int z){
    if (x < 0 || x >= a || y < 0 || y >= b || z < 0 || z >= c) return 0;
    return 1;
}
void bfs(){
    queue<box> qu;
    box now = { 0, 0, 0,0 }, temp;
    qu.push(now);
    while (qu.size()>0)
    {
        now = qu.front(); qu.pop();
        if (now.x == a - 1 && now.y == b - 1 && now.z == c - 1 && now.time <=t)
        {
            ok = 1;
            cout << now.time << endl;
            return;
        }
        for (int i = 0; i < 6; i++){
            temp.x = now.x + _move[i][0];
            temp.y = now.y + _move[i][1];
            temp.z = now.z + _move[i][2];
            temp.time = now.time + 1;
            if (!bian(temp.x,temp.y,temp.z)) continue;
            if (!s[temp.x][temp.y][temp.z]&&temp.time<=t){
                s[temp.x][temp.y][temp.z] = 1;
                if (abs(temp.x - a + 1) + abs(temp.y - b + 1) + abs(temp.z - c + 1) + temp.time>t)
                    continue;
                qu.push(temp);
            }
        }
    }
}
int main(){
    int T;
    scanf("%d", &T);
    while (T--)
    {
        ok = 0;
        cin >> a >> b >> c >> t;
        for (int i = 0; i < a; i++){
            for (int j = 0; j < b; j++){
                for (int k = 0; k < c; k++){
                    scanf("%d", &s[i][j][k]);
                }
            }
        }
        bfs();
        if (!ok) cout << -1 << endl;
    }
    return 0;
}