mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
64 lines
1.2 KiB
C++
64 lines
1.2 KiB
C++
#include<iostream>
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#include<cstdio>
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#include<cstring>
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#include<algorithm>
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using namespace std;
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#define MAXN 200200
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typedef long long LL;
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int parent[MAXN];
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LL sum[MAXN];
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int cnt[MAXN];
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struct Edge{
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int u,v,w;
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}edge[MAXN];
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int n;
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void Initiate()
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{
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memset(sum,0,(n+2)*sizeof(sum[0]));
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for(int i=0;i<=n;i++){
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parent[i]=i;
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cnt[i]=1;
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}
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}
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int Find(int x)
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{
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if(x==parent[x])
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return x;
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parent[x]=Find(parent[x]);
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return parent[x];
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}
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void Union(int r1,int r2,LL w)
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{
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parent[r1]=r2;
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cnt[r2]+=cnt[r1];
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sum[r2]+=w;
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}
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int cmp(const Edge &p,const Edge &q)
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{
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return p.w>q.w;
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}
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int main()
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{
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while(~scanf("%d",&n))
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{
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Initiate();
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for(int i=0;i<n-1;i++){
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scanf("%d%d%d",&edge[i].u,&edge[i].v,&edge[i].w);
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}
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sort(edge,edge+n-1,cmp);
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for(int i=0;i<n-1;i++){
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int r1=Find(edge[i].u);
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int r2=Find(edge[i].v);
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LL w=(LL)edge[i].w;
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LL tmp1=cnt[r2]*w+sum[r1];
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LL tmp2=cnt[r1]*w+sum[r2];
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if(tmp1>tmp2){
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Union(r2,r1,tmp1-sum[r1]);
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}else
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Union(r1,r2,tmp2-sum[r2]);
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}
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printf("%I64d\n",sum[Find(1)]);
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}
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return 0;
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}
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