【BZOJ1014】【洛谷P4036】【JSOI2008】—火星人（哈希+平衡树）

BZOJ传送门

洛谷传送门

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平衡树维护哈希值就完了
$FHQ-Treap$写烂要被卡$T$

#include<bits/stdc++.h>
using namespace std;
const int RLEN=1<<20|1;
inline char gc(){
    static char ibuf[RLEN],*ib,*ob;
    (ib==ob)&&(ob=(ib=ibuf)+fread(ibuf,1,RLEN,stdin));
    return (ib==ob)?EOF:*ib++;
}
#define gc getchar
inline int read(){
    char ch=gc();
    int res=0,f=1;
    while(!isdigit(ch))f^=ch=='-',ch=gc();
    while(isdigit(ch))res=(res+(res<<2)<<1)+(ch^48),ch=gc();
    return f?res:-res;
}
mt19937 rnd(time(NULL));
#define uint unsigned int
const int N=100005;
uint bas=233,p[N];
namespace FHQ_Treap{
    int siz[N],lc[N],rc[N],tot,rt;
    uint a[N],val[N];
    inline int newnode(int k){
        int u=++tot;siz[u]=1,val[u]=a[u]=k;
        return u;
    }
    inline void pushup(int u){
        siz[u]=siz[lc[u]]+siz[rc[u]]+1;
        val[u]=val[lc[u]]+val[rc[u]]*p[siz[lc[u]]+1]+a[u]*p[siz[lc[u]]];
    }
    inline void split(int u,int &r1,int &r2,int k){
        if(!u){r1=r2=0;return;}
        if(siz[lc[u]]>=k)
            r2=u,split(lc[u],r1,lc[r2],k);
        else
            r1=u,split(rc[u],rc[r1],r2,k-siz[lc[u]]-1);
        pushup(u);
    }
    inline void merge(int &u,int r1,int r2){
        if(!r1||!r2){u=r1+r2;return;}
        if((unsigned)rnd()%(siz[r1]+siz[r2])<siz[r1])
            u=r1,merge(rc[u],rc[r1],r2);
        else u=r2,merge(lc[u],r1,lc[r2]);
        pushup(u);
    }
    inline void insert(int p,int k){
        int r1=0,r2=0,u=newnode(k);
        split(rt,r1,r2,p);
        merge(r1,r1,u);
        merge(rt,r1,r2);
    }
    inline void update(int k,int v){
        int r1=0,r2=0,r3=0;
        split(rt,r1,r2,k-1);
        split(r2,r2,r3,1);
        a[r2]=val[r2]=v;
        merge(r1,r1,r2);
        merge(rt,r1,r3);
    }
    inline uint query(int u,int k){
        int r1=0,r2=0,r3=0;
        split(rt,r1,r2,u-1);
        split(r2,r2,r3,k);
        uint res=val[r2];
        merge(r2,r2,r3);
        merge(rt,r1,r2);
        return res;
    }
}
using namespace FHQ_Treap;
int n;
char op[4],s[N];
inline int ask(int x,int y){
    int l=1,r=siz[rt]-max(x,y)+1,res=0;
    while(l<=r){
        int mid=(l+r)>>1;
        if(query(x,mid)==query(y,mid))l=mid+1,res=mid;
        else r=mid-1;
    }return res;
}
signed main(){
    srand(time(NULL));
    p[0]=1,scanf("%s",s+1);
    for(int i=1;i<N;i++)p[i]=p[i-1]*bas;
    for(int i=1,l=strlen(s+1);i<=l;i++)insert(i-1,s[i]-'a'+1);
    n=read();
    for(int i=1;i<=n;i++){
        scanf("%s",op+1);
        if(op[1]=='Q'){
            int x=read(),y=read();
            cout<<ask(x,y)<<'\n';
        }
        else if(op[1]=='R'){
            int x=read();scanf("%s",s+1);
            update(x,s[1]-'a'+1);
        }
        else {
            int x=read();scanf("%s",s+1);
            insert(x,s[1]-'a'+1);
        }
    }
}