hdu 3191 How Many Paths Are There

http://acm.hdu.edu.cn/showproblem.php?pid=3191

这道题求次短路经和路径数

 #include <cstdio>
 #include <cstring>
 #include <vector>
 #include <queue>
 #include <algorithm>
 #define maxn 2000
 using namespace std;
 const int inf=<<;
 struct edge
 {
     int v,w;
 };

 struct node
 {
     int d,v;
     int mark;
     bool operator < (const node &a)const
     {
         if(d!=a.d)
             return d>a.d;
         return v>a.v;
     }
 };

 vector<edge>edges[maxn];
 int dis[maxn][];
 int vis[maxn][];
 int path[maxn][];
 int n,m,a,b,c,s1,f;
 node st;

 void inti()
 {
     for(int i=; i<=n; i++)
     {
         dis[i][]=dis[i][]=inf;
     }
     memset(path,,sizeof(path));
     memset(vis,false,sizeof(vis));
 }

 void dijkstra(int s,int e)
 {
     inti();
     priority_queue<node>q;
     dis[s][]=;
     path[s][]=;
     memset(vis,false,sizeof(vis));
     st.d=;
     st.v=s;
     st.mark=;
     q.push(st);
     while(!q.empty())
     {
         node st1=q.top();
         q.pop();
         if(vis[st1.v][st1.mark]) continue;
         vis[st1.v][st1.mark]=true;
         for(int i=; i<(int)edges[st1.v].size(); i++)
         {
             int v1=edges[st1.v][i].v;
             int w1=edges[st1.v][i].w;
             if(!vis[v1][]&&st1.d+w1<dis[v1][])
             {
                 if(dis[v1][]!=inf)
                 {
                     dis[v1][]=dis[v1][];
                     path[v1][]=path[v1][];
                     st.d=dis[v1][];
                     st.v=v1;
                     st.mark=;
                     q.push(st);
                 }
                 dis[v1][]=st1.d+w1;
                 path[v1][]=path[st1.v][st1.mark];
                 st.v=v1;
                 st.mark=;
                 st.d=dis[v1][];
                 q.push(st);
             }
             else if(!vis[v1][]&&st1.d+w1==dis[v1][])
             {
                 path[v1][]+=path[st1.v][st1.mark];
             }
             else if(!vis[v1][]&&st1.d+w1<dis[v1][])
             {
                 dis[v1][]=st1.d+w1;
                 path[v1][]=path[st1.v][st1.mark];
                 st.d=dis[v1][];
                 st.v=v1;
                 st.mark=;
                 q.push(st);
             }
             else if(!vis[v1][]&&st1.d+w1==dis[v1][])
             {
                 path[v1][]+=path[st1.v][st1.mark];
             }
         }
     }
 }

 int main()
 {
     while(scanf("%d%d%d%d",&n,&m,&s1,&f)!=EOF)
     {
         inti();
         for(int i=; i<=n; i++) edges[i].clear();
         for(int i=; i<m; i++)
         {
             scanf("%d%d%d",&a,&b,&c);
             edge m1;
             m1.v=b;
             m1.w=c;
             edges[a].push_back(m1);
         }
         dijkstra(s1,f);
         printf("%d %d\n",dis[f][],path[f][]);
     }
     return ;
 }