prim模板

int vis[30];
int n;
int map[30][30];
int d[30];
int prim(){  
    int i,j,mi,v;  
    for(i=0;i<n;i++){  
        d[i]=map[0][i];  
        vis[i]=0;  
    }  
    for(i=1;i<=n;i++){  
        mi=1<<30;  
        for(j=0;j<n;j++){  
            if(!vis[j] && mi>d[j]){  
                v=j;  
                mi=d[j];  
            }  
        }  
        vis[v]=1;  
        for(j=0;j<n;j++)  
            if(!vis[j] && d[j]>map[v][j])
                d[j]=map[v][j];  
    }  
    for(i=1;i<n;i++) d[0]+=d[i];  
    return d[0];  
}

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 = 10001, MAXE = 100001, INF = (~0u)>>2;
struct edge{
    int t, w, next;
}es[MAXE * 2];
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 > 1){
        if(dist[heap[k>>1]] > dist[heap[k]]){    
            swap(pos[heap[k>>1]], pos[heap[k]]);
            swap(heap[k>>1], heap[k]);
            k>>=1;
        }else
            break;
    }
}
void heapdown(int k)
{
    while((k<<1) <= size){
        int j;
        if((k<<1) == size || dist[heap[(k<<1)]] < dist[heap[(k<<1)+1]])
            j = (k<<1);
        else
            j = (k<<1) + 1;
        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[1];
    swap(pos[heap[size]], pos[heap[1]]);
    swap(heap[size], heap[1]);
    size--;
    heapdown(1);
    return ret;
}
 
int prim()
{
    int mst = 0, i, p;
    push(1, 0);
    for(i=2; i<=n; i++)
        push(i, INF);
    for(i=1; i<=n; i++){
        int t = pop();
        mst += dist[t];
        pos[t] = -1;
        for(p = h[t]; p; p = es[p].next){
            int dst = es[p].t;
            if(pos[dst] != -1 && 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=1; i<=m; i++){
        int x, y, z;
        cin>>x>>y>>z;
        addedge(x, y, z);
        addedge(y, x, z);
    }
    cout<<prim()<<endl;
    return 0;
}