CF1230 E. Kamil and Making a Stream gcd+暴力

比赛的时候TLE，第二天发现合并方向合并错了~

改了一下顺序就切了~

又掉分了，好难过QAQ......

Code:

#include <bits/stdc++.h>
#define N 100005
#define mod 1000000007
#define ll long long
#define setIO(s) freopen(s".in","r",stdin)
using namespace std;
struct Node
{
    ll gc,tmp;
    Node(ll gc=0,ll tmp=0):gc(gc),tmp(tmp){}
};
bool cmp(Node a,Node b)
{
    return a.gc < b.gc;
}
vector<Node>G[N];
vector<Node>A;
int n,edges;
ll val[N], ans=0;
int hd[N],to[N<<1],nex[N<<1];
void add(int u,int v)
{
    nex[++edges]=hd[u],hd[u]=edges,to[edges]=v;
}
void dfs(int u,int ff)
{
    if(ff!=0)
    {
        A.clear();
        for(int j=0;j<G[ff].size();++j) A.push_back(G[ff][j]);
        for(int i=0;i<A.size();++i) A[i].gc=__gcd(A[i].gc, val[u]);
    }
    A.push_back(Node(val[u], 1));
    sort(A.begin(), A.end(), cmp);
    int i,j;
    for(i=0;i<A.size();i=j)
    {
        for(j=i;j<A.size() && A[j].gc==A[i].gc;)
        {
            ++j;
        }
        ll pp=0;
        for(int k=i;k<j;++k)
        {
            pp+=A[k].tmp;
        }
        G[u].push_back(Node(A[i].gc, pp));
    }
    sort(G[u].begin(), G[u].end(), cmp);
    for(i=0;i<G[u].size();++i)
        ans=(ans+G[u][i].gc*G[u][i].tmp%mod)%mod;
    for(int i=hd[u];i;i=nex[i])
    {
        int v=to[i];
        if(v==ff) continue;
        dfs(v, u);
    }
}
int main()
{
    int i,j;
    // setIO("input");
    scanf("%d",&n);
    for(i=1;i<=n;++i) scanf("%lld",&val[i]);
    for(i=1;i<n;++i)
    {
        int a,b;
        scanf("%d%d",&a,&b), add(a,b),add(b,a);
    }
    dfs(1,0);
    printf("%lld\n",ans);
    return 0;
}