洛谷P3380 【模板】二逼平衡树（树套树，树状数组，线段树）

#include<cstdio>
#include<cstring>
#include<algorithm>
#define RG register
#define R RG int
#define II inline int
#define IV inline void
#define gc          if(++pi==iend)fread(pi=ibuf,1,SZ,stdin)
#define pc(C) *po=C;if(++po==oend)fwrite(po=obuf,1,SZ,stdout)
#define Q b+1,b+L+1
#define lb(X) X=lower_bound(Q,X)-b
using namespace std;
const int SZ=1<<20,N=50009,M=5000009,INF=2147483647;//卡了空间，M没到Nlog^2
char ibuf[SZ],obuf[SZ],*pi=ibuf+SZ-1,*po=obuf;
const char*iend=ibuf+SZ,*oend=obuf+SZ;
IV in(R&x){
    gc;
    while(*pi<‘-‘)gc;
    x=*pi&15;gc;
    while(*pi>‘-‘){x*=10;x+=*pi&15;gc;}
}
IV out(R x){
    if(x>9)out(x/10);
    pc(x%10|‘0‘);
}
int n,L,P,a[N],b[N<<1],op[N],ql[N],qr[N],qk[N];
int rt[N],lc[M],rc[M],s[M],ra[20],rs[20];
IV upd(R p,R k,R v){//更新
    for(R u,l,r,m,i=p;i<=n;i+=i&-i){
        if(!rt[i])rt[i]=++P;u=rt[i];l=1;r=L;
        while(l^r){
            s[u]+=v;m=(l+r)>>1;
            if(k<=m){r=m;if(!lc[u])lc[u]=++P;u=lc[u];}
            else  {l=m+1;if(!rc[u])rc[u]=++P;u=rc[u];}
        }
        s[u]+=v;
    }
}
II kth(R p,R k){//求第k小的值
    R i,l=1,r=L,m,sum,pa=0,ps=0;
    for(i=qr[p]  ;i;i-=i&-i)ra[++pa]=rt[i];
    for(i=ql[p]-1;i;i-=i&-i)rs[++ps]=rt[i];
    while(l^r){
        sum=0;m=(l+r)>>1;
        for(i=1;i<=pa;++i)sum+=s[lc[ra[i]]];
        for(i=1;i<=ps;++i)sum-=s[lc[rs[i]]];
        if(k<=sum){
            r=m;
            for(i=1,p=pa,pa=0;i<=p;++i)ra[++pa]=lc[ra[i]];
            for(i=1,p=ps,ps=0;i<=p;++i)rs[++ps]=lc[rs[i]];
        }
        else{
            l=m+1;k-=sum;
            for(i=1,p=pa,pa=0;i<=p;++i)ra[++pa]=rc[ra[i]];
            for(i=1,p=ps,ps=0;i<=p;++i)rs[++ps]=rc[rs[i]];
        }
    }
    return b[l];
}
II rank(R p,R x){//求离散化后的值的排名（从0计，也就是小于等于值的数的个数）
    R i,u,l,r,m,k=0;
    for(i=qr[p];i;i-=i&-i){
        u=rt[i];l=1;r=L;
        while(s[u]&&l^r){
            m=(l+r)>>1;
            if(x<=m)           r=m,u=lc[u];
            else k+=s[lc[u]],l=m+1,u=rc[u];
        }
    }
    for(i=ql[p]-1;i;i-=i&-i){
        u=rt[i];l=1;r=L;
        while(s[u]&&l^r){
            m=(l+r)>>1;
            if(x<=m)           r=m,u=lc[u];
            else k-=s[lc[u]],l=m+1,u=rc[u];
        }
    }
    return k;
}
int main(){
    R m,i,rk;
    in(n);in(m);L=n;
    for(i=1;i<=n;++i)in(a[i]);
    memcpy(b,a,(n+1)<<2);
    for(i=1;i<=m;++i){
        in(op[i]);//先存起来
        in(ql[i]);if(op[i]!=3)in(qr[i]);
        in(qk[i]);if(op[i]!=2)b[++L]=qk[i];
    }
    b[++L]=INF;sort(Q);L=unique(Q)-b-1;
    for(i=1;i<=n;++i)
        upd(i,lb(a[i]),1);
    for(i=1;i<=m;++i){
        if(op[i]!=2)lb(qk[i]);
        switch(op[i]){
            case 1:out(rank(i,qk[i])+1);pc(‘\n‘);break;
            case 2:out(kth(i,qk[i]));pc(‘\n‘);break;
            case 3:upd(ql[i],a[ql[i]],-1);
                upd(ql[i],a[ql[i]]=qk[i],1);break;
            case 4:rk=rank(i,qk[i]);
                if(rk)out(kth(i,rk));
                else{pc(‘-‘);out(INF);}pc(‘\n‘);break;
            case 5:rk=rank(i,qk[i]+1);
                out(rk>qr[i]-ql[i]?INF:kth(i,rk+1));pc(‘\n‘);
        }
    }
    fwrite(obuf,1,po-obuf,stdout);
    return 0;
}