HDU1233

hdu1233.cpp

#include <cstdio>
#include <ctime>
#include <cstdlib>
#include <iostream>
#include <cstring>
#include <vector>
#include <fstream>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>
#include <cmath>
#include <string>
#define MAX(a,b) (a>b?a:b)
#define sd(x) scanf("%d",&x)
#define sdd(a,b) scanf("%d%d",&a,&b)
#define sddd(a,b,c) scanf("%d%d%d",&a,&b,&c)
#define slflf(x,y) scanf("%lf%lf",&x,&y)
#define abs(x) (x<0?(-x):x)
#define MAX(a,b) (a>b?a:b)
#define MIN(a,b) (a<b?a:b)
using namespace std;

const int dsj_lenth = 105;

int dsj[dsj_lenth];
int graph[dsj_lenth][dsj_lenth];

void init()
{
    for (int i=0; i<dsj_lenth; i++) dsj[i]=i;
}

int Find(int x)
{
    return dsj[x]==x?x:dsj[x]=Find(dsj[x]);
}

inline void Union(int a,int b)
{
    dsj[a]=b;
}


struct road
{
    int u,v,w;
} r[dsj_lenth*dsj_lenth];

bool cmp(road a,road b)
{
    return a.w<b.w;
}


int main()
{
    int n;
    while(~sd(n) && n)
    {
        init();
        int cnt = n*(n-1)/2;
        for (int i=0;i< cnt;i++)
        {
            sd(r[i].u);
            sd(r[i].v);
            sd(r[i].w);
        }
        sort(r,r+cnt,cmp);
        int ans=0,built=0;
        for (int i=0;i<cnt;i++)
        {
            int fa = Find(r[i].u),fb=Find(r[i].v);
            if (fa!=fb)
            {
                ans+=r[i].w;
                built++;
                Union(fa,fb);
            }
            if (built==n-1) break;
        }
        cout << ans << endl;
    }
    return 0;
}