树链剖分 

 1 #include <cstdio>
 2 #include <algorithm>
 3 #include <cstring>
 4 using namespace std;
 5 
 6 const int maxn = 1e5+7;
 7 
 8 int siz[maxn],dep[maxn],top[maxn],tid[maxn],ran[maxn],fa[maxn],son[maxn];
 9 int tot ,kkk ,head[maxn];
10 
11 struct node{
12     int to,next;
13 }EE[maxn*10];
14 
15 void add_edge(int u,int v){
16     EE[kkk].to=v;EE[kkk].next=head[u];head[u]=kkk++;
17 }
18 
19 void init(){
20     memset(head,-1,sizeof(head));
21     kkk = 0;
22     tot = 0;
23 }
24 
25 void dfs1(int x,int u,int d){
26     siz[x] = 1;
27     son[x] = -1;
28     dep[x] = d;
29     fa[x] = u;
30     for(int i=head[x];i!=-1;i=EE[i].next){
31         int to = EE[i].to;
32         if(to != fa[x]){
33             dfs1(to,x,d+1);
34             siz[x] += siz[to];
35             if(son[x] == -1 || siz[to] > siz[son[x]])
36                 son[x] = to;
37         }
38     }
39 }
40 void dfs2(int x,int u){
41     top[x] = u;
42     tid[x] = ++tot;
43     ran[tot] = x;
44     if(son[x] != -1) dfs2(son[x],u);
45     for(int i=head[x];i!=-1;i=EE[i].next){
46         int to = EE[i].to;
47         if(to != son[x] && to != fa[x])
48             dfs2(to,to);
49     }
50 }
51 
52 void update(int x,int y){
53     while(top[x] != top[y]){
54         if(dep[top[x]] < dep[top[y]]) swap(x,y);
55         tre.update(1,tid[top[x]],tid[x]);
56         x = fa[top[x]];
57     }
58     if(dep[x] > dep[y]) swap(x,y);
59     if(x != y) tre.update(1,tid[son[x]],tid[y]);//给定边权值
60     ///tre.update(1,tid[x],tid[y]); //给节点权值
61 }
62 
63 int query(int x,int y){
64     int sum = -1e9-7;
65     while(top[x] != top[y]){
66         if(dep[top[x]] < dep[top[y]]) swap(x,y);
67         sum = max(sum,tre.query(1,tid[top[x]],tid[x]));
68         x = fa[top[x]];
69     }
70     if(dep[x] > dep[y]) swap(x,y);
71     if(x != y) sum = max(sum,tre.query(1,tid[son[x]],tid[y]));//给边权值
72     ///sum = max(sum,tre.query(1,tid[x],tid[y]));//给节点权值
73     return sum;
74 }

 

posted @ 2017-08-12 09:19  yZi  阅读(190)  评论(0)    收藏  举报