NOIP2014提高组 联合权值

联合权值-链接

#include<cstdio>
#define MAXN 200005
#define mod 10007
using namespace std;

inline int read(){
	int num=0,f=1;char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9')num=num*10+ch-48,ch=getchar();
	return num*f;
}

struct size{
	int v;
	int next;
}G[MAXN<<1];

struct{
	int dp1,dp2;//第一大、第二大子节点
	long long sum;//所有子节点权值的和 
	int w;//权值w 
	int fa;//父亲 
}Node[MAXN];

int head[MAXN];

long long max = 0;
long long ans = 0;
int tot = 0;
int N;


inline void add(int u,int v){
	G[++tot].v=v;G[tot].next=head[u];head[u]=tot;
}

inline void find_father_and_get_dp(int rt,int fa){
	//当前访问节点和此节点的父节点
	Node[rt].fa=fa;
	for(register int i=head[rt];i;i=G[i].next){
		int v = G[i].v;
		if(v==fa)continue;
		
		Node[rt].sum+=Node[v].w;
		
		if(Node[v].w>Node[rt].dp1){//如果大于dp1 
			Node[rt].dp2 = Node[rt].dp1;//更新dp2 
			Node[rt].dp1 = Node[v].w;//更新dp1 
		}
		else if(Node[v].w>Node[rt].dp2){//如果不大于dp1又大于dp2 
			Node[rt].dp2 = Node[v].w;//更新dp2 
		}
		
		find_father_and_get_dp(v,rt);//递归 
	}
}

inline void dfs(int rt,int fa){
	
	if(fa>1){
		long long w = ((long long)Node[Node[fa].fa].w*Node[rt].w);
		if(w>max)max=w;
		ans = (ans + (w<<1)) % mod; 
	}
	
	long long dp = (long long)Node[rt].dp1*Node[rt].dp2;
	if(dp>max)max=dp;
		
	for(register int i=head[rt];i;i=G[i].next){
		int v = G[i].v;if(v==fa)continue;
		long long sum = Node[rt].sum - Node[v].w;
		ans = (ans + (long long)Node[v].w*sum) % mod;
 		dfs(v,rt);
	}
} 

int main(){
	
	N=read();
	int u,v;
	for(register int i=1;i<N;++i){
		u=read();v=read();add(u,v);add(v,u);
	}
	
	for(register int i=1;i<=N;++i){
		Node[i].w=read();
		Node[i].dp1=0;Node[i].dp2=0;
		Node[i].sum=0;
	}

	
	find_father_and_get_dp(1,0);
	dfs(1,0);
	
	printf("%lld %lld",max,ans);
	return 0;
}