prim+heap模板

先扔在这里，还没具体搞懂

#include<bits/stdc++.h>#define MAXN 1200#define MAXM 120000#define INF 19930317int e[MAXM], cost[MAXM], next[MAXM], g[MAXN], size;struct node{    int d, v;}heap[MAXN];int pos[MAXN], hl;int m, n;void swap(int a, int b){    heap[0] = heap[a];    heap[a] = heap[b];    heap[b] = heap[0];    pos[heap[a].v] = a;    pos[heap[b].v] = b;}void heapfy(){    int i = 2;    while (i <= hl)    {        if ((i < hl) && (heap[i + 1].d < heap[i].d))            i++;        if (heap[i].d < heap[i >> 1].d)        {            swap(i, i >> 1);            i <<= 1;        }        else            break;    }}void decrease(int i){    heap[0] = heap[i];    while ((i > 1) && (heap[0].d < heap[i >> 1].d))    {        heap[i] = heap[i >> 1];        pos[heap[i].v] = i;        i >>= 1;    }    heap[i] = heap[0];    pos[heap[i].v] = i;}void delete_min(){    swap(1, hl);    hl--;    heapfy();}void relax(int v, int w){    if (w < heap[pos[v]].d)    {        heap[pos[v]].d = w;        decrease(pos[v]);    }}void insert(int u, int v, int w){    e[++size] = v;    cost[size] = w;    next[size] = g[u];    g[u] = size;}void init(){    int i, u, v, w;    size = 0;    memset(g, 0, sizeof(g));    for (i = 1; i <= m; i++)    {        scanf("%d%d%d", &u, &v, &w);        insert(u, v, w);        insert(v, u, w);    }}int prim(){    int mst = 0, u , p, i;    for (i = 1; i <= n; i++)    {        pos[i] = heap[i].v = i;        heap[i].d = INF;    }    heap[1].d = 0;    hl = n;    while (hl)    {        u = heap[1].v;        mst += heap[1].d;        delete_min();        for (p = g[u]; p; p = next[p])            if (pos[e[p]] <= hl)                relax(e[p], cost[p]);    }    return mst;}int main(){    while (scanf("%d%d", &n, &m) == 2 && n)    {        init();        printf("%d\n", prim());    }}