模板LCT

Posted 2020-09-12

LCT用来解决树的形态可变的树上操作查询问题

 1 #include<stdio.h>
 2 #include<algorithm>
 3 using namespace std;
 4 struct node{int ch[2],fa,siz;bool rev;};
 5 node sp[200005];
 6 int n,op,fa[200005];
 7 bool isro(int x){return x!=sp[sp[x].fa].ch[0]&&x!=sp[sp[x].fa].ch[1];}
 8 void pushup(int x){sp[x].siz=sp[sp[x].ch[0]].siz+sp[sp[x].ch[1]].siz+1;};
 9 void pushdown(int);
10 void Pushdown(int);
11 void rot(int);
12 void splay(int);
13 void access(int);
14 void maker(int x){access(x);splay(x);sp[x].rev^=1;}
15 void link(int x,int y){maker(x);sp[x].fa=y;splay(x);}
16 void cut(int x,int y){maker(x);access(y);splay(y);sp[y].ch[0]=sp[x].fa=0;}
17 int main()
18 {
19     scanf("%d",&n);
20     int i,p,x,y;
21     for(i=1;i<=n;i++)
22     {
23         scanf("%d",&p);
24         fa[i]=sp[i].fa = min(i+p,n+1);
25         sp[i].siz = 1;
26     }
27     sp[n+1].siz = 1;
28     scanf("%d",&op);
29     for(i=1;i<=op;i++)
30     {
31         scanf("%d%d",&p,&x); x++;
32         if(p==1)
33         {
34             maker(n+1);
35             access(x);splay(x);
36             printf("%d\n",sp[sp[x].ch[0]].siz);
37         }
38         else
39         {
40             scanf("%d",&y);
41             cut(x,fa[x]);
42             link(x,min(n+1,y+x));
43             fa[x] = min(n+1,y+x);
44         }
45     }
46     return 0;
47 }
48 void rot(int now)
49 {
50     int fa=sp[now].fa;int fafa=sp[fa].fa; bool isr=(now==sp[fa].ch[1]);
51     if(!isro(fa)){sp[fafa].ch[fa==sp[fafa].ch[1]]=now;}
52     sp[now].fa = fafa;
53     sp[fa].ch[isr] = sp[now].ch[!isr];
54     sp[sp[now].ch[!isr]].fa = fa;
55     sp[now].ch[!isr] = fa;sp[fa].fa = now;
56     pushup(fa); pushup(now);
57 }
58 void pushdown(int now)
59 {
60     if(sp[now].rev)
61     {
62         int lc = sp[now].ch[0],rc=sp[now].ch[1];
63         if(lc) sp[lc].rev^=1;
64         if(rc) sp[rc].rev^=1;
65         sp[now].ch[0]=rc,sp[now].ch[1]=lc;
66         sp[now].rev = false;
67     }
68 }
69 void Pushdown(int now)
70 {
71     if(!isro(now)) Pushdown(sp[now].fa);
72     pushdown(now);
73 } 
74 void splay(int now)
75 {
76     Pushdown(now);
77     while(!isro(now))
78     {
79         if(!isro(sp[now].fa)) rot(now);
80         rot(now);
81     }
82 }
83 void access(int x)
84 {
85     for(int t=0;x;t=x,x=sp[x].fa)
86     {
87         splay(x);
88         sp[x].ch[1] = t;
89     }
90 }

View Code