Description
4月16日，日本熊本地区强震后，受灾严重的阿苏市一养猪场倒塌，幸运的是，猪圈里很多头猪依然坚强存活。当地15名消防员耗时一天解救围困的“猪坚强”。不过与在废墟中靠吃木炭饮雨水存活36天的中国汶川“猪坚强”相比，熊本的猪可没那么幸运，因为它们最终还是没能逃过被送往屠宰场的命运。
我们假设“猪坚强”被困在一个N*M的废墟中，其中“@”表示“猪坚强”的位置，“.”表示可以直接通过的空地，“#”表示不能拆毁的障碍物，“*”表示可以拆毁的障碍物，那么请问消防员至少要拆毁多少个障碍物，才能从废墟中救出“猪坚强”送往屠宰场？（当“猪坚强”通过空地或被拆毁的障碍物移动到废墟边缘时，视作被救出废墟）
Input
多组数据，第一行有一个整数T，表示有T组数据。（T<=100）
以下每组数据第一行有两个整数N和M。(1<=N,M<=100)
接着N行，每行有一个长度为M的字符串。
Output
一个整数，为最少拆毁的障碍物数量,如果不能逃离废墟，输出-1。
Sample Input
3 3 3 ### #@* *** 3 4 #### #@.* **.* 3 3 .#. #@# .#.
Sample Output
1 0 -1
代码：
#include<iostream> #include<queue> using namespace std; struct Node{ int x; int y; int z; }; struct cmp{ bool operator()(Node a,Node b){ return a.z > b.z; } }; char ch[100][101]; int main(){ int t; cin >> t; while(t--){ int n,m; cin >> n >> m; for(int i = 0;i < n;i++) cin >> ch[i]; int a,b; a = -1; for(int i = 0;i < n;i++){ for(int j = 0;j < m;j++){ if(ch[i][j] == '@'){ a = i; b = j; break; } } if(a != - 1) break; } priority_queue<Node,vector<Node>,cmp> q; int ans = -1; struct Node *node = new struct Node; node->x = a; node->y = b; node->z = 0; q.push(*node); ch[node->x][node->y] = '#'; bool flag = false; while(!q.empty()){ struct Node *now = new struct Node; *now = q.top(); q.pop(); // cout << "now " << now->x << " " << now->y << " " << now->z << endl; if(now->x == 0 || now->x == n - 1 || now->y == 0 || now->y == m - 1){ ans = now->z; break; } else{ if(now->y - 1 >= 0){ if(ch[now->x][now->y - 1] == '.'){ struct Node *temp = new struct Node; temp->x = now->x; temp->y = now->y - 1; temp->z = now->z; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x][now->y - 1] = '#'; } else if(ch[now->x][now->y - 1] == '*'){ struct Node *temp = new struct Node; temp->x = now->x; temp->y = now->y - 1; temp->z = now->z + 1; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x][now->y - 1] = '#'; } } if(now->y + 1 <= m - 1){ if(ch[now->x][now->y + 1] == '.'){ struct Node *temp = new struct Node; temp->x = now->x; temp->y = now->y + 1; temp->z = now->z; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x][now->y + 1] = '#'; } else if(ch[now->x][now->y + 1] == '*'){ struct Node *temp = new struct Node; temp->x = now->x; temp->y = now->y + 1; temp->z = now->z + 1; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x][now->y + 1] = '#'; } } if(now->x - 1 >= 0){ if(ch[now->x - 1][now->y] == '.'){ struct Node *temp = new struct Node; temp->x = now->x - 1; temp->y = now->y; temp->z = now->z; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x - 1][now->y] = '#'; } else if(ch[now->x - 1][now->y] == '*'){ struct Node *temp = new struct Node; temp->x = now->x - 1; temp->y = now->y; temp->z = now->z + 1; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x - 1][now->y] = '#'; } } if(now->x + 1 <= n - 1){ if(ch[now->x + 1][now->y] == '.'){ struct Node *temp = new struct Node; temp->x = now->x + 1; temp->y = now->y; temp->z = now->z; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x + 1][now->y] = '#'; } else if(ch[now->x + 1][now->y] == '*'){ struct Node *temp = new struct Node; temp->x = now->x + 1; temp->y = now->y; temp->z = now->z + 1; q.push(*temp); // cout << "push " << temp->x << " " << temp->y << " " << temp->z << endl; ch[now->x + 1][now->y] = '#'; } } } } cout << ans << endl; } return 0; }