Format of the query is "2 v w". You must change the value of vertex v to w. You are given all the queries, help Caisa to solve the problem.
Input The first line contains two space-separated integers n, q (1?≤?n,?q?≤?105).
The second line contains n integers a1,?a2,?...,?an (1?≤?ai?≤?2?106), where ai represent the value of node i.
Each of the next n?-?1 lines contains two integers xi and yi (1?≤?xi,?yi?≤?n; xi?≠?yi), denoting the edge of the tree between vertices xi and yi.
Each of the next q lines contains a query in the format that is given above. For each query the following inequalities hold: 1?≤?v?≤?n and 1?≤?w?≤?2?106. Note that: there are no more than 50 queries that changes the value of a vertex.
Output For each query of the first type output the result of the query.
Sample test(s) input 4 6
10 8 4 3
1 2
2 3
3 4
1 1
1 2
1 3
1 4
2 1 9
1 4
output -1
1
2
-1
1
Note gcd(x,?y) is greatest common divisor of two integers x and y.
【分析】这道题是做现场赛的。本来能A的,但是太紧张了=而且也不会用vector,边表搞的麻烦死了。
开始看到修改操作才50次、时间又松,真是爽!估计每次可以暴力重构这颗树,然后对于每个质因子记录最优值。
首先每次不能sqrt的效率枚举一个数的因子,我们可以预处理出每个数的所有质因子。(其实有更省空间的)
剩下来要解决的问题是:因为我是用dfs的,怎么把某个子树的信息在搜完后再去掉?(以免影响其他子树)HHD表示用vector一点也不虚。其实应该也可以用边表类似的思路,但是麻烦= =
【代码】
#include
#include
#include
#include
#define N 100005 #define S 2000005 #define push push_back #define pop pop_back using namespace std; vector
fac[S],f[S]; int data[N],ans[N],end[N],pf[S],deep[N]; int C,cnt,n,Q,i,x,y,opt; struct arr{int go,next;}a[N*2]; inline void add(int u,int v){a[++cnt].go=v;a[cnt].next=end[u];end[u]=cnt;} inline void init() { int H=2000000; for (int i=2;i<=H;i++) if (!pf[i]) { for (int j=i;j<=H;j+=i) fac[j].push(i),pf[j]=1; } } void dfs(int k,int fa) { int P=data[k]; for (int i=0;i
deep[ans[k]]) ans[k]=f[go][temp-1]; f[go].push(k); } for (int i=end[k];i;i=a[i].next) if (a[i].go!=fa) dfs(a[i].go,k); for (int i=0;i