最小生成树 Kruskal 算法模板

/*Kruskal 算法 *注意：点是从1到n编号 *Ecnt = 0  */typedef int weight_t;const int SIZE_V = const int SIZE_E = int Father[SIZE_V];int Ecnt = 0;//int n;  // 此处写点的全局变量//并查集算法void init(int vn){    for(int i = 0;i <= vn;++i)        Father[i] = i;}int find(int x){    return (Father[x] == x) ? x :         Father[x] = find(Father[x]);}inline void unite(int x,int y){    Father[find(y)] = Father[find(x)];}struct edge_t{    int s,e;    weight_t w;    friend bool operator < (edge_t const&a,edge_t const&b){        if (a.w != b.w) return a.w < b.w;        if (a.s != b.s) return a.s < b.s;        return a.e < b.e;    }}Edge[SIZE_E];inline void mkEdge(int a,int b,weight_t w){    if (a > b)swap(a,b);    Edge[Ecnt].s = a;    Edge[Ecnt].e = b;    Edge[Ecnt++].w = w;}weight_t Kruskal(int vn,int en){    init(vn);    sort(Edge,Edge+en);    weight_t ret = 0;    for (int i = 0;i < en; ++i){        if ( find(Edge[i].s) == find(Edge[i].e))            continue;        ret += Edge[i].w;        unite(Edge[i].s,Edge[i].e);        --vn;        if (1 == vn)break;    }    return ret;}