prim模板

int vis[];
int n;
int map[][];
int d[];
int prim(){
    int i,j,mi,v;
    for(i=;i<n;i++){
        d[i]=map[][i];
        vis[i]=;
    }
    for(i=;i<=n;i++){
        mi=<<;
        for(j=;j<n;j++){
            if(!vis[j] && mi>d[j]){
                v=j;
                mi=d[j];
            }
        }
        vis[v]=;
        for(j=;j<n;j++)
            if(!vis[j] && d[j]>map[v][j])
                d[j]=map[v][j];
    }
    for(i=;i<n;i++) d[]+=d[i];
    return d[];
}

heap优化

http://www.nocow.cn/index.php/Prim%E7%AE%97%E6%B3%95

 /*
 二叉堆优化Prim算法
 Author:YangZX
 Date：9.11 2011
 */
 #include <iostream>
 using namespace std;
 const int MAXV = , MAXE = , INF = (~0u)>>;
 struct edge{
     int t, w, next;
 }es[MAXE * ];
 int h[MAXV], cnt, n, m, heap[MAXV], size, pos[MAXV], dist[MAXV];
 void addedge(int x, int y, int z)
 {
     es[++cnt].t = y;
     es[cnt].next = h[x];
     es[cnt].w = z;
     h[x] = cnt;
 }

 void heapup(int k)
 {
     while(k > ){
         if(dist[heap[k>>]] > dist[heap[k]]){
             swap(pos[heap[k>>]], pos[heap[k]]);
             swap(heap[k>>], heap[k]);
             k>>=;
         }else
             break;
     }
 }
 void heapdown(int k)
 {
     while((k<<) <= size){
         int j;
         if((k<<) == size || dist[heap[(k<<)]] < dist[heap[(k<<)+]])
             j = (k<<);
         else
             j = (k<<) + ;
         if(dist[heap[k]] > dist[heap[j]]){
             swap(pos[heap[k]], pos[heap[j]]);
             swap(heap[k], heap[j]);
             k=j;
         }else
             break;
     }
 }
 void push(int v, int d)
 {
     dist[v] = d;
     heap[++size] = v;
     pos[v] = size;
     heapup(size);
 }
 int pop()
 {
     int ret = heap[];
     swap(pos[heap[size]], pos[heap[]]);
     swap(heap[size], heap[]);
     size--;
     heapdown();
     return ret;
 }

 int prim()
 {
     int mst = , i, p;
     push(, );
     for(i=; i<=n; i++)
         push(i, INF);
     for(i=; i<=n; i++){
         int t = pop();
         mst += dist[t];
         pos[t] = -;
         for(p = h[t]; p; p = es[p].next){
             int dst = es[p].t;
             if(pos[dst] != - && dist[dst] > es[p].w){
                 dist[dst] = es[p].w;
                 heapup(pos[dst]);
                 heapdown(pos[dst]);
             }
         }
     }
     return mst;
 }
 int main()
 {
     cin>>n>>m;
     for(int i=; i<=m; i++){
         int x, y, z;
         cin>>x>>y>>z;
         addedge(x, y, z);
         addedge(y, x, z);
     }
     cout<<prim()<<endl;
     return ;
 }