poj 1511 正向 反向 构两个图

  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=1000010;
 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 u[MAXN] , v[MAXN] , w[MAXN] ;
 31 int n ;
 32 void Dijkstra(int start)//点的编号从1开始
 33 {
 34     memset(vis,false,sizeof(vis));
 35     for(int i=1;i<=n;i++)dist[i]=INF;
 36     priority_queue<qnode>que;
 37     while(!que.empty())que.pop();
 38     dist[start]=0;
 39     que.push(qnode(start,0));
 40     qnode tmp;
 41     while(!que.empty())
 42     {
 43         tmp=que.top();
 44         que.pop();
 45         int u=tmp.v;
 46         if(vis[u])continue;
 47         vis[u]=true;
 48         for(int i=0;i<E[u].size();i++)
 49         {
 50             int v=E[tmp.v][i].v;
 51             int cost=E[u][i].cost;
 52             if(!vis[v]&&dist[v]>dist[u]+cost)
 53             {
 54                 dist[v]=dist[u]+cost;
 55                 que.push(qnode(v,dist[v]));
 56             }
 57         }
 58     }
 59 }
 60 void addedge(int u,int v,int w)
 61 {
 62     E[u].push_back(Edge(v,w));
 63 }
 64 
 65 int main ()
 66 {
 67    // freopen("in.txt","r",stdin) ;
 68     int m ;
 69     int T ;
 70     scanf("%d" , &T) ;
 71     while (T--)
 72     {
 73         scanf("%d %d" , &n , &m) ;
 74         LL ans = 0 ;
 75         int i , j ;
 76         for(i=1;i<=m;i++)
 77             scanf("%d%d%d" , &u[i] , &v[i] , &w[i]) ;
 78 
 79         for(i=1;i<=n;i++)
 80             E[i].clear();
 81         for(i=1;i<=m;i++)
 82             addedge(u[i],v[i],w[i]) ;
 83         Dijkstra(1) ;
 84         for(i=1;i<=n;i++)
 85             ans += dist[i] ;
 86 
 87         for(i=1;i<=n;i++)
 88             E[i].clear();
 89         for(i=1;i<=m;i++)
 90             addedge(v[i],u[i],w[i]) ;
 91         Dijkstra(1) ;
 92         for(i=1;i<=n;i++)
 93             ans += dist[i] ;
 94 
 95         cout<<ans<<endl ;
 96 
 97     }
 98 
 99     return 0 ;
100 }