POJ 1251 Jungle Roads(最小生成树简单题)

题意分析：

模板题了吧。

#include<iostream>#include<cstdio>#include<algorithm>#include<vector>using namespace std;#define MAX 30struct edge { int u, v, cost; };bool cmp(const edge& e1, const edge& e2) { return e1.cost < e2.cost; }vector<edge>es;//边集合int fa[MAX];//并查集int n;//顶点数int find(int x) { return fa[x] == -1 ? x : fa[x] = find(fa[x]); }//并查集查找 路径压缩int kk(){int cnt = 0;sort(es.begin(), es.end(), cmp);//对边进行排序memset(fa, -1, sizeof(fa));//并查集初始化int res = 0;for (int i = 0; i < es.size(); i++){if (find(es[i].u) != find(es[i].v))//不在同一个连通分量{fa[find(es[i].u)] = find(es[i].v);//uniteres += es[i].cost;}}return res;}int main(){int n;while (cin >> n,n){es.clear();for (int i = 0; i < n - 1; i++){char c1, c2; int k,v,d;cin >> c1 >> k;while (k--){cin >> c2 >> d;v = c2 - 'A';edge tmp = { i,v,d };es.push_back(tmp);}}cout << kk() << endl;}system("pause");}