萌新刚学OI$(\dfrac{7.12}{((\dfrac{(66ccff)_{16}\times （20120712)_8}{2012^{-0712}+\dfrac{(1)_2}{(0x66ccff)_{16}+(0712)_8}})^{-2023.10.29}+\dfrac{1}{(0712)_8})})^{\dfrac{1}{0x66ccff}}$天，可持久化线段树求调

80pts,MLE两个点

#include<bits/stdc++.h>
#define mid (l+r)/2
#define int long long
using namespace std;
int n,q,m,cnt = 0;
int a[0x66ccf],b[0x66ccf],T[0x66ccf];
int sum[0x66ccff],L[0x66ccff],R[0x66ccff];
inline int read(){
    int s = 0,w = 1;char ch = getchar();
    while(ch<'0'||ch>'9'){ if(ch ==  '-') w = -1;ch = getchar();}
    while(ch>='0'&&ch<='9'){ s = s*10+ch-'0';ch = getchar();}
    return s*w;
}
inline int build(int l, int r){
    int rt=++cnt;
    sum[rt]=0;
    if(l<r){
        L[rt]=build(l, mid);
        R[rt]=build(mid+1, r);
    }
    return rt;
}
inline int change(int q, int l, int r, int x){
    int rt=++cnt;
    L[rt]=L[q];
    R[rt]=R[q];
    sum[rt]=sum[q]+1;
    if(l<r){
        if(x<=mid) L[rt]=change(L[q],l,mid,x);
        else R[rt]=change(R[q],mid+1,r,x);
    }
    return rt;
}
inline int ask(int u, int v, int l, int r, int k){
    if (l>=r) 
        return l;
    int x=sum[L[v]]-sum[L[u]];
    if (x>=k) 
        return ask(L[u], L[v], l, mid, k);
    return ask(R[u], R[v], mid+1, r, k-x);
}

signed main(){
    n=read(),q=read();
    for (int i = 1; i <= n; i ++){
        scanf("%d", &a[i]);
        b[i] = a[i];
    }
    sort(b+1, b+1+n);
    m=unique(b+1, b+1+n)-b-1;
    T[0]=build(1, m);
    for(int i = 1; i <= n; i ++){
        int t = lower_bound(b+1, b+1+m, a[i])-b;
        T[i] = change(T[i-1], 1, m, t);
    }
    while(q--){
        int x=read(),y=read(),z=read();
        int t = ask(T[x-1], T[y], 1, m, z);
        cout<<b[t]<<endl;
    }
}