hdu1879最小生成树+并查集

#include<iostream>
#include<vector>
#include<queue>
#include<cstdio>

using namespace std;

struct edge
{
    int from,to,cost;
    friend bool operator <(edge e1,edge e2)
    {
        return e1.cost>e2.cost;
    }
};
const int MAXN=111;
int u[MAXN];
vector<edge>v[MAXN];
bool selected[MAXN];
//bool select_e[MAXN][MAXN];
int find(int p)
{
    if(u[p]==p)
    {
        return p;
    }else
    {
        return u[p]=find(u[p]);
    }
}
void connect(int a,int b)
{
    int f1=find(a);
    int f2=find(b);
    int i=0;
    if(f1<f2)
    {
        u[f2]=f1;
        for(i=0;i<=int(v[f2].size())-1;i++)
        {
            v[f1].push_back(v[f2][i]);
        }
    }else
    {
        u[f1]=f2;
        for(i=0;i<=int(v[f1].size())-1;i++)
        {
            v[f2].push_back(v[f1][i]);
        }
    }
}
int prim(int p)
{
    priority_queue<edge>q;
    int sum=0;
    p=find(p);
    selected[p]=1;
    int i=0;
    while(!q.empty())
    {
        q.pop();
    }
    for(i=0;i<=int(v[p].size())-1;i++)
    {
        int to=find(v[p][i].to);
        if(!selected[to])
        {
            q.push(v[p][i]);
        }
    }
    while(!q.empty())
    {
        int from;
        int i=0;
        int to;
        edge e=q.top();
        to=find(e.to);
        from=find(e.from);
        q.pop();
        if(!selected[to])
        {
            sum=sum+e.cost;
            selected[to]=1;
            for(i=0;i<=int(v[to].size())-1;i++)
            {
                int too=find(v[to][i].to);
                if(!selected[too])
                {
                    q.push(v[to][i]);
                }
            }
        }
    }
    return sum;
}
void init(int n)
{
    int i=0;
    for(i=0;i<=n;i++)
    {
        v[i].clear();
    }
    memset(selected,0,sizeof(selected));
//    memset(select_e,0,sizeof(select_e));
    for(i=0;i<=n;i++)
    {
        u[i]=i;
    }
}
int main()
{
    int n;
    while((scanf("%d",&n))&&(n!=0))
    {
        int from,to,cost,builded;
        init(n);
        int i=0;
        n=(n*(n-1))/2;
        for(i=0;i<=n-1;i++)
        {
            scanf("%d%d%d%d",&from,&to,&cost,&builded);
            from=find(from);
            to=find(to);
            if(builded)
            { 
                connect(from,to);
            }else
            {
                edge e={from,to,cost};
                v[e.from].push_back(e);
                swap(e.from,e.to);
                v[e.from].push_back(e);
            }
        }
        cout<<prim(find(1))<<endl;
    }
    return  0;
}