HDU 1072 Nightmare

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

 

题目有点长呀~~读懂题目其实就好做了。

题目大意就是：在n×m的地图上，0表示墙，1表示空地，2表示人，3表示目的地，4表示有定时炸弹重启器。定时炸弹的时间是6，人走一步所需要的时间是1。每次可以上、下、左、右移动一格。当人走到4时如果炸弹的时间不是0，可以重新设定炸弹的时间为6。如果人走到3而炸弹的时间不为0时，成功走出。求人从2走到3的最短时间。但是要注意的是：地图可以重复访问，但是实际上，如果是对于地图上是4的点，重复去访问的话，没有意义，因为如果走的出去，走一遍是4的就可以了，重复去走只会增加步数，而如果走不出去。。。更没必要了，所以，可以对4的点进行标记。

//Asimple
#include <iostream>
#include <sstream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cctype>
#include <cstdlib>
#include <stack>
#include <cmath>
#include <set>
#include <map>
#include <string>
#include <queue>
#include <limits.h>
#include <time.h>
using namespace std;
const int maxn = 10;
int dx[] = {-1,1,0,0}, dy[]={0,0,-1,1};
typedef long long ll;
int n, m, num, T, k, x, y, len, ans;
int endx, endy;
int Map[maxn][maxn];


struct node{
    int x;
    int y;
    int step;
    int time;
};
node start;

bool wrong(int x, int y) {
    return x<0 || x>=n || y<0 || y>=m || !Map[x][y];
}

void BFS() {
    queue<node> q;
    node now, next;
    q.push(start);
    while( !q.empty() ) {
        now = q.front();
        q.pop();
        for(int i=0; i<4; i++) {
            next.step = now.step+1;
            next.time = now.time-1;
            next.x = now.x + dx[i];
            next.y = now.y + dy[i];
            if( !wrong(next.x, next.y) && next.time>0 ) {
                if( Map[next.x][next.y] == 3 ) {
                    cout << next.step << endl;
                    return ;
                } else if( Map[next.x][next.y] == 4 ) {
                    next.time = 6;
                    Map[next.x][next.y] = 0;
                }
                q.push(next);
            }
        }
    }
    cout << -1 << endl;
}

void input() {
    cin >> T ;
    while( T -- ) {
        cin >> 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 ) {
                    start.x = i;
                    start.y = j;
                }
            }
        }
        start.step = 0;
        start.time = 6;
        BFS();
    } 
}

int main(){
    input();
    return 0;
}