hdu 2544 hdu 1874 poj 2387 Dijkstra 模板题

hdu 2544 

求点1到点n的最短路  无向图

Sample Input
2 1 //结点数 边数
1 2 3 //u v w
3 3
1 2 5
2 3 5
3 1 2
0 0

Sample Output
3
2

 

堆优化Dijstra模板

 1 # include <iostream>
 2 # include <cstdio>
 3 # include <cstring>
 4 # include <algorithm>
 5 # include <cmath>
 6 # include <queue>
 7 # define LL long long
 8 using namespace std ;
 9 
10 const int INF=0x3f3f3f3f;
11 const int MAXN=110;
12 struct qnode
13 {
14     int v;
15     int c;
16     qnode(int _v=0,int _c=0):v(_v),c(_c){}
17     bool operator <(const qnode &r)const
18     {
19         return c>r.c;
20     }
21 };
22 struct Edge
23 {
24     int v,cost;
25     Edge(int _v=0,int _cost=0):v(_v),cost(_cost){}
26 };
27 vector<Edge>E[MAXN];
28 bool vis[MAXN];
29 int dist[MAXN];
30 int n ;
31 void Dijkstra(int start)//点的编号从1开始
32 {
33     memset(vis,false,sizeof(vis));
34     for(int i=1;i<=n;i++)dist[i]=INF;
35     priority_queue<qnode>que;
36     while(!que.empty())que.pop();
37     dist[start]=0;
38     que.push(qnode(start,0));
39     qnode tmp;
40     while(!que.empty())
41     {
42         tmp=que.top();
43         que.pop();
44         int u=tmp.v;
45         if(vis[u])continue;
46         vis[u]=true;
47         for(int i=0;i<E[u].size();i++)
48         {
49             int v=E[tmp.v][i].v;
50             int cost=E[u][i].cost;
51             if(!vis[v]&&dist[v]>dist[u]+cost)
52             {
53                 dist[v]=dist[u]+cost;
54                 que.push(qnode(v,dist[v]));
55             }
56         }
57     }
58 }
59 void addedge(int u,int v,int w)
60 {
61     E[u].push_back(Edge(v,w));
62 }
63 
64 int main ()
65 {
66    // freopen("in.txt","r",stdin) ;
67     int m ;
68     while (scanf("%d %d" , &n , &m) !=EOF)
69     {
70         if (n==0 && m==0)
71             break ;
72         int u , v , w ;
73         int i , j ;
74         for(i=1;i<=n;i++)
75             E[i].clear();
76 
77          while(m--)
78         {
79             scanf("%d%d%d" , &u , &v , &w) ;
80             addedge(u,v,w) ;
81             addedge(v,u,w) ;
82         }
83         Dijkstra(1) ;
84         printf("%d\n" , dist[n]) ;
85     }
86 
87     return 0 ;
88 }

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