UVA12538

https://uva.onlinejudge.org/index.php

　　可持久化fhp-treap。像线段树的可持久化一样自上至下，每次新建log(n)个节点即可。

#include<bits/stdc++.h>
const int maxn=50015,maxlen=115;
using namespace std;
int n,cnt;
struct Ttreap{
    int tot,ver;
    static const int maxnode=10000015;
    struct Tnode{
        Tnode *c[2];
        int key,siz;char ch;
        void update(){siz=c[0]->siz+c[1]->siz+1;}
    }T[maxnode],*null,*root[maxn];
    int seed(){return 1ll*rand()*rand()%19990211;}
    void clear(){
        tot=ver=0;null=T;
        null->c[0]=null->c[1]=null;null->siz=0;
        for (int i=0;i<=n;++i) root[i]=null;
    }
    Tnode *newnode(Tnode *x){
        if (x==null) return null;
        Tnode *cur=T+(++tot);
        *cur=*x;return cur;
    }
    Tnode *newnode(char ch){
        Tnode *cur=T+(++tot);
        cur->c[0]=cur->c[1]=null;
        cur->ch=ch;cur->siz=1;cur->key=seed();
        return cur;
    }
    Tnode *merge(Tnode *x,Tnode *y){
        Tnode *t;
        if (x==null) return newnode(y);
        if (y==null) return newnode(x);
        if (x->key<y->key){t=newnode(x);t->c[1]=merge(x->c[1],y);}
        else{t=newnode(y);t->c[0]=merge(x,y->c[0]);}
        t->update();return t;
    }
    void split(Tnode *x,Tnode *&a,Tnode *&b,int rank){
        if (!rank){a=null;b=newnode(x);}
        else if (x->siz<=rank){a=newnode(x);b=null;}
        else if (rank<=x->c[0]->siz){b=newnode(x);split(x->c[0],a,b->c[0],rank);b->update();}
        else{a=newnode(x);split(x->c[1],a->c[1],b,rank-x->c[0]->siz-1);a->update();}
    }
    Tnode *build(char s[]){
        static Tnode *stk[maxlen];int top=0;
        for (int i=1;s[i];++i){
            Tnode *cur=newnode(s[i]),*last=null;
            while (top&&cur->key<stk[top]->key){stk[top]->update();last=stk[top--];}
            cur->c[0]=last;cur->update();
            if (top){stk[top]->c[1]=cur;stk[top]->update();}
            stk[++top]=cur;
        }
        while (top) stk[top--]->update();
        return stk[1];
    }
    void insert(int pos,char s[]){
        Tnode *a,*b;
        root[++ver]=build(s);
        split(root[ver-1],a,b,pos);
        root[ver]=merge(a,root[ver]);
        root[ver]=merge(root[ver],b);
    }
    void remove(int pos,int l){
        ++ver;
        Tnode *a,*b,*c,*d;
        split(root[ver-1],a,b,pos-1);split(b,c,d,l);
        root[ver]=merge(a,d);
    }
    void print(Tnode *x){
        if (x->c[0]!=null) print(x->c[0]);
        putchar(x->ch);cnt+=(x->ch=='c');
        if (x->c[1]!=null) print(x->c[1]);
    }
    void query(int v,int pos,int l){
        Tnode *a,*b,*c,*d;
        split(root[v],a,b,pos-1);
        split(b,c,d,l);print(c);putchar('
');
    }
}treap;
void insert(){
    int p;char q[maxlen];
    scanf("%d%s",&p,q+1);
    q[strlen(q+1)+1]=0;
    p-=cnt;treap.insert(p,q);
}
void remove(){
    int p,c;scanf("%d%d",&p,&c);
    p-=cnt;c-=cnt;treap.remove(p,c);
}
void query(){
    int v,p,c;scanf("%d%d%d",&v,&p,&c);
    v-=cnt;p-=cnt;c-=cnt;treap.query(v,p,c);
}
int main(){
    srand((unsigned)time(NULL));
    scanf("%d",&n);treap.clear();
    for (int t,i=1;i<=n;++i){
        scanf("%d",&t);
        switch (t){
            case 1:insert();break;
            case 2:remove();break;
            case 3:query();break;
        }
    }
    return 0;
}