夏天的伞

Problem DescriptionThere are Nvillages, which are numbered from 1 to N, and you should build some roads suchthat every two villages can connect to each other. We say two village A and Bare connected

次小生成树，可通过最小生成树求得。最小生成树得到后，把某一未利用的边加入树中，则会形成一个环，把这个环上其余的最大边去掉，就会得到这个加入这个边的次小生成树。把所有的未利用的边遍历，取最小值，就会得到次小生成树。附poj1679的代码：#include#include#includeusing namespace std;const int maxn=105;