hdu Rescue (bfs)

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1242

简单优先队列搜索,自己好久不敲,,,,,手残啊,,,,orz

代码:

 #include <stdio.h>
 #include <string.h>
 #include <math.h>
 #include <algorithm>
 #include <iostream>
 #include <ctype.h>
 #include <iomanip>
 #include <queue>
 #include <stdlib.h>
 using namespace std;

 int N,M,ans;
 char mp[][];
 int vis[][];

 int dx[]={,,-,};
 int dy[]={-,,,};

 int sx,sy;
 int ex,ey;

 struct Node
 {
     int x,y;
     int step;
 };

 bool operator<(Node a,Node b)//定义结构体类型的优先队列的优先级,从小到大
 {
     return a.step>b.step;
 }

 void getMap(int n,int m)
 {
     for(int i=;i<n;i++)
         for(int j=;j<m;j++)
         {
             cin>>mp[i][j];
             if(mp[i][j]=='r')
             {
                 sx=i;
                 sy=j;
             }
             if(mp[i][j]=='a')
             {
                 ex=i;
                 ey=j;
             }
         }
 }  

 bool pd(int x,int y)
 {
     if(x>=&&x<N&&y>=&&y<M&&!vis[x][y]&&mp[x][y]!='#')
         return true;
     return false;
 } 

 int bfs(int x,int y)
 {
     memset(vis,,sizeof(vis));
     priority_queue<Node>q;
     Node a,b;
     a.x=x,a.y=y,a.step=;
     q.push(a);
     while(!q.empty()){
         b=q.top();
         q.pop();
         for(int i=; i<; i++){
             int px=b.x+dx[i];
             int py=b.y+dy[i];
             if(pd(px,py)){
                 vis[px][py]=;
                 a.x=px;
                 a.y=py;
                 if(mp[px][py]=='x'){
                     a.step=b.step+;
                     q.push(a);
                 }
                 else
                 {
                     a.step=b.step+;
                     q.push(a);
                     if(px==ex && py==ey)
                         return a.step;
                 }
             }
         }
     }
     return -;
 }

 int main()
 {

     while(cin>>N>>M){
     getMap(N,M);
     int ans=bfs(sx,sy);
     if(ans==-)
         printf("Poor ANGEL has to stay in the prison all his life.\n");
     else
         printf("%d\n",ans);
     }
 }

优先队列搜索:

 ///优先队列是默认int从大到小priority_queue<int>q1，也可以定义为从小到大priority_queue<int,vector<int>,greater<int> >q2;
 也可以自定义优先级，重载<

 #include <iostream>
 #include <functional>
 #include <queue>
 using namespace std;

 ///自定义优先级，两种写法,按照优先级从大到小的顺序
 /*
 struct node
 {
     friend bool operator<(node n1,node n2)
     {
         return n1.priority<n2.priority;
     }
     int priority;
     int value;
 };*/

 struct node
 {
     int priority;
     int value;
 };
 bool operator<(node a,node b)
 {
     return a.priority<b.priority;
 }

 int main()
 {
     const int len=;
     int i;
     int a[len]={,,,,};
     //优先队列中从大到小输出
     priority_queue<int>q1;
     for(i=;i<len;i++)
         q1.push(a[i]);
     for(int i=;i<len;i++)
     {
         cout<<q1.top();
         q1.pop();
     }
     cout<<endl;
     //优先队列中从小到大输出

     /**
     priority_queue<int,vector<int>,greater<int> >q2;
     for(i=0;i<len;i++)
         q2.push(a[i]);
     for(i=0;i<len;i++)
     {
         cout<<q2.top();
         q2.pop();
     }*/

     priority_queue<int,vector<int>,greater<int> >q;
     for(int i=;i<len;i++)
         q.push(a[i]);
     while(!q.empty())
     {
         cout<<q.top();
         q.pop();
     }
     cout<<endl;
     //按照某个优先级输出,该代码中为priority值大的先输出
     priority_queue<node>q3;
     node b[len];
     b[].priority=;b[].value=;
     b[].priority=;b[].value=;
     b[].priority=;b[].value=;
     b[].priority=;b[].value=;
     b[].priority=;b[].value=;
     for(i=;i<len;i++)
         q3.push(b[i]);
     cout<<"优先级"<<'\t'<<"值"<<endl;
     for(i=;i<len;i++)
     {
         cout<<q3.top().priority<<'\t'<<q3.top().value<<endl;
         q3.pop();
     }
     return ;
 }

可见链接:http://blog.csdn.net/sr_19930829/article/details/42706469

运行：

96532
23569

优先级  值
9       5
8       2
6       1
2       3
1       4