Luogu P3369 【模板】普通平衡树
作者:互联网
解法
就是最普通的splay啦,直接放代码QAQ
代码
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#define INF 0x3f3f3f3f
using namespace std;
typedef long long LL;
const int N=1e5+5;
int read()
{
int x=0,p=1; char ch=getchar();
while((ch<'0'||ch>'9')&&ch!='-') ch=getchar();
if(ch=='-') p=-1,ch=getchar();
while(ch>='0'&&ch<='9') x=(x<<3)+(x<<1)+ch-'0',ch=getchar();
return x*p;
}
int ch[N][2],par[N],val[N],cnt[N],siz[N],tot,root;
int chk(int x) { return ch[par[x]][1]==x; }
void pushup(int x) { siz[x]=siz[ch[x][0]]+siz[ch[x][1]]+cnt[x]; }
int rotate(int x)
{
int y=par[x],z=par[y],k=chk(x),w=ch[x][k^1];
ch[z][chk(y)]=x,par[x]=z;
ch[y][k]=w,par[w]=y;
ch[x][k^1]=y,par[y]=x;
pushup(y),pushup(x);
}
void splay(int x,int goal)
{
int y,z;
while(par[x]!=goal)
{
y=par[x],z=par[y];
if(z!=goal)
chk(x)==chk(y) ? rotate(y):rotate(x);
rotate(x);
}
if(!goal) root=x;
}
void find(int x)
{
int u=root;
while(ch[u][x>val[u]] && x!=val[u])
u=ch[u][x>val[u]];
splay(u,0);
}
void insert(int x)
{
int u=root,p=0;
while(u && val[u]!=x) p=u,u=ch[u][x>val[u]];
if(u) cnt[u]++;
else
{
u=++tot;
if(p) ch[p][x>val[p]]=u;
ch[u][0]=ch[u][1]=0;
par[u]=p; val[u]=x;
cnt[u]=siz[u]=1;
}
splay(u,0);
}
int kth(int k)
{
int u=root;
if(k>siz[u]) return 0;
for(; ;)
{
if(ch[u][0] && k<=siz[ch[u][0]])
u=ch[u][0];
else if(k>siz[ch[u][0]]+cnt[u])
k-=siz[ch[u][0]]+cnt[u],u=ch[u][1];
else
return u;
}
}
int Next(int x,int f)
{
find(x);
int u=root;
if(val[u]>x && f) return u;
if(val[u]<x && !f) return u;
u=ch[u][f];
while(ch[u][f^1]) u=ch[u][f^1];
return u;
}
void remove(int x)
{
int last=Next(x,0),next=Next(x,1);
splay(last,0),splay(next,last);
int del=ch[next][0];
if(cnt[del]>1)
cnt[del]--,splay(del,0);
else
ch[next][0]=0,pushup(next),pushup(root);
}
int main()
{
int n,op,x;
n=read();
insert(INF);
insert(-INF);
while(n--)
{
op=read(),x=read();
switch (op)
{
case 1: insert(x); break ;
case 2: remove(x); break ;
case 3: find(x); printf("%d\n",siz[ch[root][0]]); break ;
case 4: printf("%d\n",val[kth(x+1)]); break ;
case 5: printf("%d\n",val[Next(x,0)]); break ;
case 6: printf("%d\n",val[Next(x,1)]); break ;
}
}
return 0;
}
标签:case,ch,val,int,Luogu,break,P3369,&&,模板 来源: https://www.cnblogs.com/lzqlalala/p/10958820.html