[BZOJ3223]文艺平衡树（平衡树splay）

来源：互联网发布：三菱系统编程视频教程编辑：程序博客网时间：2024/05/05 15:18

题目描述

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题解

平衡树的模板题。有区间操作，打标记。

代码

#include<iostream>#include<cstring>#include<cstdio>using namespace std;const int max_n=1e5+5;const int INF=1e9;int n,m,x,y;int root,sz;int ch[max_n][2],f[max_n],delta[max_n],size[max_n],key[max_n];int a[max_n];inline bool get(int x){    return ch[ f[x] ][1]==x;}inline void update(int x){    size[x]=size[ ch[x][0] ]+size[ ch[x][1] ]+1;}inline void pushdown(int x){    if (x&&delta[x]){        delta[ ch[x][0] ]^=1;        delta[ ch[x][1] ]^=1;        swap(ch[x][0],ch[x][1]);        delta[x]=0;    }}inline void rotate(int x){    pushdown(f[x]);    pushdown(x);    int old=f[x],oldf=f[old],which=get(x);    ch[old][which]=ch[x][which^1];    f[ ch[old][which] ]=old;    ch[x][which^1]=old;    f[old]=x;    f[x]=oldf;    if (oldf)      ch[oldf][ ch[oldf][1]==old ]=x;    update(old);    update(x);}inline void splay(int x,int tar){    for (int fa;(fa=f[x])!=tar;rotate(x))      if (f[fa]!=tar)        rotate( (get(x)==get(fa)) ?fa:x );    if (tar==0) root=x;}inline int build(int l,int r,int fa){    if (l>r) return 0;    int mid=(l+r)>>1;    int now=++sz;    key[now]=a[mid]; f[now]=fa; delta[now]=0;    int lch=build(l,mid-1,now);    int rch=build(mid+1,r,now);    ch[now][0]=lch;    ch[now][1]=rch;    update(now);    return now;}inline int find(int x){    int now=root;    while (1){        pushdown(now);        if (x<=size[ch[now][0]])          now=ch[now][0];        else{            x-=size[ ch[now][0] ]+1;            if (!x) return now;            now=ch[now][1];        }    }}inline void print(int now){    pushdown(now);    if (ch[now][0]) print(ch[now][0]);    if (key[now]!=-INF&&key[now]!=INF)      printf("%d ",key[now]);    if (ch[now][1]) print(ch[now][1]);}int main(){    scanf("%d%d",&n,&m);    a[1]=-INF; a[n+2]=INF;    for (int i=1;i<=n;++i)      a[i+1]=i;    root=build(1,n+2,0);    for (int i=1;i<=m;++i){        scanf("%d%d",&x,&y);        int aa=find(x);        int bb=find(y+2);        splay(aa,0);        splay(bb,aa);        delta[ ch[ ch[root][1] ][0] ]^=1;    }    print(root);}

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