HDU 1009 The Shortest Path in Nya Graph

　　迪杰斯特拉 + 优先队列

　　

  1 #include <iostream>
  2 #include <cstdio>
  3 #include <cstring>
  4 #include <algorithm>
  5 #include <cmath>
  6 #include <queue>
  7 #include <vector>
  8 
  9 #define LL __int64
 10 
 11 const LL INF = 2000000000;
 12 
 13 using namespace std;
 14 
 15 LL dis[300100];
 16 
 17 int head[300100];
 18 
 19 struct E
 20 {
 21     int u,v,w,next;
 22 }edge[1001000];
 23 
 24 int top;
 25 
 26 void link(int u,int v,int w)
 27 {
 28     edge[top].u = u;
 29     edge[top].v = v;
 30     edge[top].w = w;
 31     edge[top].next = head[u];
 32     head[u] = top++;
 33 }
 34 
 35 struct HeapNode
 36 {
 37     int d,u;
 38     bool operator < (const HeapNode& rhs) const{
 39         return d>rhs.d;
 40     }
 41 };
 42 
 43 void dij(int st,int n)
 44 {
 45     priority_queue<HeapNode> q;
 46 
 47     HeapNode p;
 48 
 49     p.d = 0;
 50     p.u = 1;
 51 
 52     q.push(p);
 53 
 54     while(q.empty() == false)
 55     {
 56         HeapNode x = q.top();
 57         q.pop();
 58 
 59         int u = x.u;
 60 
 61         st = head[u];
 62 
 63         while(st != -1)
 64         {
 65             if(dis[u] + edge[st].w < dis[edge[st].v])
 66             {
 67                 dis[edge[st].v] = edge[st].w + dis[u];
 68 
 69                 HeapNode temp;
 70 
 71                 temp.d = dis[edge[st].v];
 72                 temp.u = edge[st].v;
 73                 q.push(temp);
 74             }
 75             st = edge[st].next;
 76 
 77         }
 78     }
 79 
 80     if(dis[n] == INF)
 81         cout<<"-1"<<endl;
 82     else
 83         cout<<dis[n]<<endl;
 84 }
 85 
 86 int main()
 87 {
 88     int i,n,m,c,u,v,w;
 89     int T,icase = 0;
 90 
 91     cin>>T;
 92     while(T--)
 93     {
 94         scanf("%d %d %d",&n,&m,&c);
 95 
 96         memset(head,-1,(n*3+2)*sizeof(int));
 97 
 98         top = 0;
 99 
100         for(i = 1;i <= n; ++i)
101         {
102             scanf("%d",&u);
103 
104             link(n+2*u-1,i,0);
105             link(i,n+u*2,0);
106         }
107 
108         for(i = 1;i < n; ++i)
109         {
110             link(n+i*2+2,n+i*2-1,c);
111             link(n+i*2,n+i*2+1,c);
112         }
113 
114         for(i = 1;i <= m; ++i)
115         {
116             scanf("%d %d %d",&u,&v,&w);
117             link(u,v,w);
118             link(v,u,w);
119         }
120 
121         for(i = 1,n *= 3;i <= n; ++i)
122         {
123             dis[i] = INF;
124         }
125 
126         dis[1] = 0;
127 
128         printf("Case #%d: ",++icase);
129         dij(1,n/3);
130 
131     }
132     return 0;
133 }
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　　墨迹了一下午 效率低了一13

posted @ 2013-09-12 20:26  好小孩  阅读(172)  评论(0)  编辑  收藏  举报