HDU 3371 Connect the Cities
Problem Description
In 2100, since the sea level rise, most of the cities disappear. Though some survived cities are still connected with others, but most of them become disconnected. The government wants to build some roads to connect all of these cities again, but they don’t
want to take too much money.
Input
The first line contains the number of test cases.
Each test case starts with three integers: n, m and k. n (3 <= n <=500) stands for the number of survived cities, m (0 <= m <= 25000) stands for the number of roads you can choose to connect the cities and k (0 <= k <= 100) stands for the number of still connected
cities.
To make it easy, the cities are signed from 1 to n.
Then follow m lines, each contains three integers p, q and c (0 <= c <= 1000), means it takes c to connect p and q.
Then follow k lines, each line starts with an integer t (2 <= t <= n) stands for the number of this connected cities. Then t integers follow stands for the id of these cities.
Output
For each case, output the least money you need to take, if it’s impossible, just output -1.
Sample Input
1
6 4 3
1 4 2
2 6 1
2 3 5
3 4 33
2 1 2
2 1 3
3 4 5 6
Sample Output
1
題意：給你n m k; 最小生成樹的經典輸入，k的意思代表給定有k條路已經連通了。現在要你求出連通所有路的最小價值
思路：最小生成樹的變形，只要用並查集把已經連通的點放到一起就可以了，再最小生成樹算法
AC代碼：
#include
#include
#include
using namespace std;
int n,m,cnt;
int f[520];
int flag[520];
#define N 25005
struct node
{
int u,v,w;
}num[N];
bool cmp(node x,node y)
{
return x.w
