bzoj2002 弹飞绵羊

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LCT 裸题，技巧是反着建边才能维护向下路径
/**************************************************************    Problem: 2002    User: Clare    Language: C++    Result: Accepted    Time:1884 ms    Memory:6036 kb****************************************************************/ #include <cstdio>#include <iostream>#include <algorithm>#include <cstring>#include <cmath>#include <queue>#include <vector>#include <stack>using namespace std; #define N 200010 int n,m;int size[N],fa[N],c[N][2],Next[N];bool Rev[N];stack<int> st; inline int read(){    int x=0,f=1;char ch=getchar();    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}    while(ch<='9'&&ch>='0'){x=x*10+ch-'0';ch=getchar();}    return x*f;} void Pushup(int k){    int l=c[k][0],r=c[k][1];    size[k]=size[l]+size[r]+1;} void Pushdown(int k){    int l=c[k][0],r=c[k][1];    if(Rev[k])    {        Rev[k]^=1;Rev[r]^=1;Rev[l]^=1;        swap(c[k][0],c[k][1]);    }} bool Pd_root(int k){    return !(c[fa[k]][0]==k)&&!(c[fa[k]][1]==k);} void Rotate(int x){    int y=fa[x],z=fa[y],l,r;    if(c[y][0]==x)l=0;else l=1;    r=l^1;    if(Pd_root(y));    else if(c[z][0]==y)c[z][0]=x;    else c[z][1]=x;    fa[x]=z;fa[y]=x;fa[c[x][r]]=y;    c[y][l]=c[x][r];c[x][r]=y;    Pushup(y);Pushup(x);} void Splay(int x){    st.push(x);    for(int i=x;!Pd_root(i);i=fa[i])    {        st.push(fa[i]);    }    while(!st.empty())    {        int now=st.top();st.pop();        Pushdown(now);    }    while(!Pd_root(x))    {        int y=fa[x],z=fa[y];        if(!Pd_root(y))        {            if(c[y][0]==x^c[z][0]==y)                Rotate(x);            else Rotate(y);        }        Rotate(x);    }} void Access(int x){    for(int t=0;x;t=x,x=fa[x])        Splay(x),c[x][1]=t,Pushup(x);} void Move_to_root(int x){    Access(x);Splay(x);Rev[x]^=1;} void Join(int x,int y){    Move_to_root(x);fa[x]=y;} void Cut(int x,int y){    Move_to_root(x);Access(y);Splay(y);    fa[x]=0;c[y][0]=0;    Pushup(y);} void Split(int x,int y){    Move_to_root(x);Access(y);Splay(y);} int main(){    n=read();    for(int i=1;i<=n+1;i++)        size[i]=1;    for(int i=1;i<=n;i++)    {        int x=read();        if(i+x>n)            fa[i]=n+1,Next[i]=n+1;        else fa[i]=i+x,Next[i]=i+x;    }    m=read();    for(int i=1;i<=m;i++)    {        int kind=read();        if(kind==1)        {            int x=read()+1;            Move_to_root(n+1);Access(x);Splay(x);            printf("%d\n",size[c[x][0]]);        }        else        {            int x=read()+1,y=read();            if(x+y>n)                y=n+1;            else y=x+y;            Cut(x,Next[x]);Join(x,y);            Next[x]=y;        }    }    return 0;}
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