ZOJ 3659 Conquer a New Region[长春区域赛]

并查集好题，第一次写这种类型的题
#pragma comment(linker, "/STACK:102400000,102400000")
#include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
#include<queue>
#include<stack>
#include<string>
#include<map>
#include<set>
#include<cmath>
#include<cassert>
#include<cstring>
#include<iomanip>
using namespace std;
#ifdef _WIN32
#define i64 __int64
#define out64 "%I64d\n"
#define in64 "%I64d"
#else
#define i64 long long
#define out64 "%lld\n"
#define in64 "%lld"
#endif
/************ for topcoder by zz1215 *******************/
#define FOR(i,a,b)      for( int i = (a) ; i <= (b) ; i ++)
#define FF(i,a)        for( int i = 0 ; i < (a) ; i ++)
#define FFD(i,a,b)      for( int i = (a) ; i >= (b) ; i --)
#define S64(a)          scanf(in64,&a)
#define SS(a)           scanf("%d",&a)
#define LL(a)           ((a)<<1)
#define RR(a)           (((a)<<1)+1)
#define pb              push_back
#define CL(Q)           while(!Q.empty())Q.pop()
#define MM(name,what)   memset(name,what,sizeof(name))
#define MC(a,b)     memcpy(a,b,sizeof(b))
#define MAX(a,b)        ((a)>(b)?(a):(b))
#define MIN(a,b)        ((a)<(b)?(a):(b))
#define read            freopen("in.txt","r",stdin)
#define write           freopen("out.txt","w",stdout)

const int inf = 0x3f3f3f3f;
const i64 inf64 = 0x3f3f3f3f3f3f3f3fLL;
const double oo = 10e9;
const double eps = 10e-9;
const double pi = acos(-1.0);
const int maxn = 400011;

struct zz
{
    int x;
    int y;
    i64 c;
    bool operator < (const zz & cmp ) const
    {
        return c > cmp.c;
    }
}zx;

int n;
int f[maxn];
i64 s[maxn];
i64 dp[maxn];
vector<zz>v;

pair<int,i64> find(int x)
{
    if(x==f[x])
    {
        return make_pair(x,0);
    }
    else
    {
        pair<int,i64> re=find(f[x]);
        dp[x]+=re.second;
        f[x]=re.first;
        return make_pair(f[x],dp[x]);
    }
}

i64 start()
{
    int now,to;
    for(int i=0;i<v.size();i++)
    {
        now = find(v[i].x).first;
        to = find(v[i].y).first;
        dp[now] = s[to]*v[i].c;
        f[now]=i+n+1;
        dp[to] = s[now]*v[i].c;
        f[to]=i+n+1;
        s[i+n+1]=s[now]+s[to];
    }
    i64 ans=0;
    for(int i=1;i<=n;i++)
    {
        ans = max(ans,find(i).second);
    }
    return ans;
}

int main()
{
    while(cin>>n)
    {
        v.clear();
        for(int i=1;i<=n-1;i++)
        {
            SS(zx.x);SS(zx.y);SS(zx.c);
            v.pb(zx);
        }
        sort(v.begin(),v.end());
        for(int i=1;i<=2*n-1;i++)
        {
            f[i]=i;
            dp[i]=0;
            s[i]=1;
        }
        cout<<start()<<endl;
    }
    return 0;
}

补充：软件开发 , C++ ,