3728 联合权值[NOIP 2014 Day1 T2]

来源：NOIP2014 Day1 T2

OJ链接：

http://codevs.cn/problem/3728/

https://www.luogu.org/problemnew/show/P1351

 #include<iostream>
 #include<cstdio>
 #define N 200010
 #define P 10007
 using namespace std;
 struct use{int st,en;}e[N*];
 long long ans,w[N],maxx;
 int cnt,n,a,b,point[N],next[N*];
 void add(int x,int y){
   next[++cnt]=point[x];point[x]=cnt;
   e[cnt].st=x;e[cnt].en=y;
 }
 int main(){
    scanf("%d",&n);
    for (int i=;i<=n-;i++){scanf("%d%d",&a,&b);add(a,b);add(b,a);}
    for (int i=;i<=n;i++) scanf("%lld",&w[i]);
    for (int i=;i<=n;i++){
      long long tp1(),tp2(),mx1(-),mx2(-);
      for (int j=point[i];j;j=next[j]){
        (tp1+=w[e[j].en])%=P;(tp2+=w[e[j].en]*w[e[j].en])%=P;
        if (mx1<w[e[j].en]){mx2=mx1;mx1=w[e[j].en];}
        else mx2=max(mx2,w[e[j].en]);
      }
      (ans+=(tp1*tp1)%P-tp2+P)%=P;maxx=max(maxx,mx1*mx2);
    }
    cout<<maxx<<' '<<ans<<endl;
 }