link cut tree
比bzoj2049多维护一个size
注意查询之前要把n+1reverse一下，保证答案正确性
1 #include<algorithm> 2 #include<iostream> 3 #include<cstdlib> 4 #include<cstring> 5 #include<cstdio> 6 #include<string> 7 #include<cmath> 8 #include<ctime> 9 #include<queue> 10 #include<stack> 11 #include<map> 12 #include<set> 13 #define rre(i,r,l) for(int i=(r);i>=(l);i--) 14 #define re(i,l,r) for(int i=(l);i<=(r);i++) 15 #define Clear(a,b) memset(a,b,sizeof(a)) 16 #define inout(x) printf("%d",(x)) 17 #define douin(x) scanf("%lf",&x) 18 #define strin(x) scanf("%s",(x)) 19 #define LLin(x) scanf("%lld",&x) 20 #define op operator 21 #define CSC main 22 typedef unsigned long long ULL; 23 typedef const int cint; 24 typedef long long LL; 25 using namespace std; 26 void inin(int &ret) 27 { 28 ret=0;int f=0;char ch=getchar(); 29 while(ch<'0'||ch>'9'){if(ch=='-')f=1;ch=getchar();} 30 while(ch>='0'&&ch<='9')ret*=10,ret+=ch-'0',ch=getchar(); 31 ret=f?-ret:ret; 32 } 33 int ch[200020][2],fa[200020],s[200020],rev[200020]; 34 bool isroot(int x){return ch[fa[x]][0]!=x&&ch[fa[x]][1]!=x;} 35 void maintain(int x){if(x)s[x]=1+s[ch[x][0]]+s[ch[x][1]];} 36 void down(int x) 37 { 38 if(rev[x]) 39 { 40 swap(ch[x][0],ch[x][1]); 41 rev[ch[x][0]]^=1; 42 rev[ch[x][1]]^=1; 43 rev[x]=0; 44 } 45 } 46 void rotate(int x) 47 { 48 int y=fa[x],z=fa[y]; 49 if(!isroot(y))ch[z][ch[z][1]==y]=x; 50 fa[x]=z,fa[y]=x; 51 int d=ch[y][1]==x; 52 fa[ch[x][d^1]]=y; 53 ch[y][d]=ch[x][d^1]; 54 ch[x][d^1]=y; 55 maintain(y),maintain(x); 56 } 57 int sta[200020],top; 58 void splay(int x) 59 { 60 top=0;sta[++top]=x;int xx=x; 61 while(!isroot(xx))sta[++top]=fa[xx],xx=fa[xx]; 62 while(top)down(sta[top--]); 63 while(!isroot(x)) 64 { 65 int y=fa[x],z=fa[y]; 66 if(!isroot(y)) 67 if((ch[y][1]==x)^(ch[z][1]==y))rotate(x); 68 else rotate(y);else ; 69 rotate(x); 70 } 71 } 72 void access(int x) 73 { 74 int temp=0; 75 while(x) 76 { 77 splay(x); 78 ch[x][1]=temp; 79 temp=x,x=fa[x]; 80 } 81 } 82 void reverse(int x) 83 { 84 access(x),splay(x),rev[x]^=1; 85 } 86 void link(int x,int y) 87 { 88 reverse(x),fa[x]=y,splay(x); 89 } 90 void cut(int x,int y) 91 { 92 reverse(x),access(y),splay(y),ch[y][0]=fa[x]=0; 93 } 94 int find(int x) 95 { 96 access(x),splay(x); 97 int y=x; 98 while(ch[y][0])y=ch[y][0]; 99 return y; 100 } 101 int n,m,x,a[200020]; 102 int main() 103 { 104 inin(n);re(i,1,n+1)s[i]=1; 105 re(i,1,n) 106 { 107 inin(a[i]);a[i]=min(a[i]+i,n+1); 108 link(i,a[i]); 109 } 110 inin(m); 111 re(i,1,m) 112 { 113 int opt,q,w; 114 inin(opt); 115 if(opt==1) 116 { 117 reverse(n+1); 118 inin(q);q++; 119 access(q),splay(q); 120 printf("%d ",s[ch[q][0]]); 121 } 122 else 123 { 124 inin(q),inin(w);q++; 125 cut(q,a[q]);a[q]=min(w+q,n+1); 126 link(q,a[q]); 127 } 128 } 129 return 0; 130 }