Problem Description

Ignatius had a nightmare last night. He found himself in a labyrinth with a time bomb on him. The labyrinth has an exit, Ignatius should get out of the labyrinth before the bomb explodes. The initial exploding time of the bomb is set to 6 minutes. To prevent the bomb from exploding by shake, Ignatius had to move slowly, that is to move from one area to the nearest area(that is, if Ignatius stands on (x,y) now, he could only on (x+1,y), (x-1,y), (x,y+1), or (x,y-1) in the next minute) takes him 1 minute. Some area in the labyrinth contains a Bomb-Reset-Equipment. They could reset the exploding time to 6 minutes.

Given the layout of the labyrinth and Ignatius’ start position, please tell Ignatius whether he could get out of the labyrinth, if he could, output the minimum time that he has to use to find the exit of the labyrinth, else output -1.

Here are some rules:
1. We can assume the labyrinth is a 2 array.
2. Each minute, Ignatius could only get to one of the nearest area, and he should not walk out of the border, of course he could not walk on a wall, too.
3. If Ignatius get to the exit when the exploding time turns to 0, he can’t get out of the labyrinth.
4. If Ignatius get to the area which contains Bomb-Rest-Equipment when the exploding time turns to 0, he can’t use the equipment to reset the bomb.
5. A Bomb-Reset-Equipment can be used as many times as you wish, if it is needed, Ignatius can get to any areas in the labyrinth as many times as you wish.
6. The time to reset the exploding time can be ignore, in other words, if Ignatius get to an area which contain Bomb-Rest-Equipment, and the exploding time is larger than 0, the exploding time would be reset to 6.

Input

The input contains several test cases. The first line of the input is a single integer T which is the number of test cases. T test cases follow. Each test case starts with two integers N and M(1<=N,Mm=8) which indicate the size of the labyrinth. Then N lines follow, each line contains M integers. The array indicates the layout of the labyrinth. There are five integers which indicate the different type of area in the labyrinth: 0: The area is a wall, Ignatius should not walk on it. 1: The area contains nothing, Ignatius can walk on it. 2: Ignatius’ start position, Ignatius starts his escape from this position. 3: The exit of the labyrinth, Ignatius’ target position. 4: The area contains a Bomb-Reset-Equipment, Ignatius can delay the exploding time by walking to these areas.

Output

For each test case, if Ignatius can get out of the labyrinth, you should output the minimum time he needs, else you should just output -1.

Sample Input

3

3 3

2 1 1

1 1 0

1 1 3

4 8

2 1 1 0 1 1 1 0

1 0 4 1 1 0 4 1

1 0 0 0 0 0 0 1

1 1 1 4 1 1 1 3

5 8

1 2 1 1 1 1 1 4

1 0 0 0 1 0 0 1

1 4 1 0 1 1 0 1

1 0 0 0 0 3 0 1

1 1 4 1 1 1 1 1

Sample Output

4

-1

13

这道题也算是比较简单的搜索题，题意是说需要在炸弹爆炸之前走出迷宫，如果迷宫为“4”，炸弹爆炸时间重置为6，“0”是墙，“1”是路，“2”为入口，“3”为出口，需要注意的就是时间的计算。

#include<iostream>
#include<stdio.h>
#include<math.h>
#include<algorithm>
#include<queue>
#include<string.h>
using namespace std;
int map[10][10];
int dir[][2] = { -1,0,1,0,0,1,0,-1 };//方向座标
int n, m, bx, by;
struct zzz
{
    int x, y, time, time1;//time为炸弹时间，time1为走迷宫的时间
} t, z;
void bfs()//广搜
{
    queue<zzz>q;
    z.x = bx;
    z.y = by;
    z.time = 6;//炸弹初始时间为6s
    z.time1 = 0;//记录走的时间
    q.push(z);
    while (!q.empty())
    {
        z = q.front();
        q.pop();
        for (int i = 0; i < 4; i++)
        {
            t.x = z.x + dir[i][0];
            t.y = z.y + dir[i][1];
            t.time = z.time - 1;
            t.time1 = z.time1 + 1;
            if (t.x >= 0 && t.x < n&&t.y >= 0 && t.y < m&&map[t.x][t.y] != 0 && t.time>0)//判断是否越界和超时
            {
                if (map[t.x][t.y] == 3)//如果为3，则输出走的时间
                {
                    printf("%d\n", t.time1);
                    return;
                }
                if (map[t.x][t.y] == 4)//为4，重置炸弹爆炸时间
                {
                    t.time = 6;
                    map[t.x][t.y] = 0;
                }
                q.push(t);
            }
        }
    }
    printf("-1\n");
}
int main()
{
    int sss;
    cin >> sss;
    while (sss--)
    {
        scanf("%d%d", &n, &m);
        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < m; j++)
            {
                cin >> map[i][j];
                if (map[i][j] == 2)//记录初始位置
                {
                    bx = i;
                    by = j;
                }
            }
        }
        bfs();