C - Ilya And The Tree Codeforces Round #430 (Div. 2)

http://codeforces.com/contest/842/problem/C

树 dp

一个数的质因数有限，用set存储，去重

 #include <cstdio>
 #include <cstdlib>
 #include <cmath>
 #include <cstring>
 #include <time.h>
 #include <string>
 #include <set>
 #include <map>
 #include <list>
 #include <stack>
 #include <queue>
 #include <vector>
 #include <bitset>
 #include <ext/rope>
 #include <algorithm>
 #include <iostream>
 using namespace std;
 #define ll long long
 #define minv 1e-6
 #define inf 1e9
 #define pi 3.1415926536
 #define E  2.7182818284
 const ll mod=1e9+;//
 const int maxn=2e5+;

 struct node
 {
     int d;
     node* next;
 }*e[maxn];

 set<int>y[maxn]; //delete one
 int a[maxn],x[maxn],value[maxn];
 bool vis[maxn]={};

 void dfs(int d)
 {
     set<int>::iterator i;
     int dd;

     value[d]=x[d];
     for (i=y[d].begin();i!=y[d].end();i++)
         value[d]=max(value[d],*i);

     node* p=e[d];
     vis[d]=;
     while (p)
     {
         dd=p->d;
         if (!vis[dd])
         {
             x[dd]=__gcd(x[d],a[dd]);
             y[dd].insert(x[d]);
             for (i=y[d].begin();i!=y[d].end();i++)
                 y[dd].insert(__gcd(a[dd],*i));
             if (d==)
                 y[dd].insert(a[dd]);
             dfs(dd);
         }
         p=p->next;
     }
     //free memory
     y[d].clear();
 }

 int main()
 {
     node* p;
     int n,X,y,i;
     scanf("%d",&n);
     for (i=;i<=n;i++)
         scanf("%d",&a[i]);
     for (i=;i<n;i++)
     {
         scanf("%d%d",&X,&y);
         p=(node*) malloc (sizeof(node));
         p->d=y;
         p->next=e[X];
         e[X]=p;

         p=(node*) malloc (sizeof(node));
         p->d=X;
         p->next=e[y];
         e[y]=p;
     }

     x[]=a[];
     dfs();

     for (i=;i<n;i++)
         printf("%d ",value[i]);
     printf("%d",value[i]);
     return ;
 }
 /*
 3
 6 10 12
 1 2
 2 3
 */