luogu 3834 【模板】可持久化线段树 1（主席树）

我这种菜鸡还是%一下棒神比较好

 #include<iostream>
 #include<cstdio>
 #include<cmath>
 #include<cstdlib>
 #include<cstring>
 #include<algorithm>
 #include<vector>
 #include<queue>
 #define inf 2139062143
 #define ll long long
 #define MAXN 200100
 using namespace std;
 inline int read()
 {
     int x=,f=;char ch=getchar();
     while(!isdigit(ch)) {if(ch=='-') f=-;ch=getchar();}
     while(isdigit(ch)) {x=x*+ch-'';ch=getchar();}
     return x*f;
 }
 int n,T,cnt;
 struct node{int ls,rs,sum;}tr[MAXN<<];
 struct data{int val,pos;}g[MAXN];
 bool cmp(data a,data b) {return a.val<b.val;}
 int rt[MAXN],rnk[MAXN];
 void inst(int &k,int x,int l,int r)
 {
     //cout<<"I : "<<k<<" "<<x<<" "<<l<<" "<<r<<" "<<cnt<<endl;
     tr[++cnt]=tr[k];
     k=cnt,tr[k].sum++;
     if(l==r) return ;
     int mid=(l+r)>>;
     if(x<=mid) inst(tr[k].ls,x,l,mid);
     else inst(tr[k].rs,x,mid+,r);
 }
 int query(int k,int a,int b,int l,int r)
 {
     //cout<<"Q : "<<k<<" "<<a<<" "<<b<<" "<<l<<" "<<r<<endl;
     int res=tr[tr[b].ls].sum-tr[tr[a].ls].sum;
     if(l==r) return l;
     int mid=(l+r)>>;
     if(k<=res) return query(k,tr[a].ls,tr[b].ls,l,mid);
     else return query(k-res,tr[a].rs,tr[b].rs,mid+,r);
 }
 int main()
 {
     n=read(),T=read();int a,b,c;
     for(int i=;i<=n;i++) g[i].val=read(),g[i].pos=i;
     sort(g+,g+n+,cmp);
     for(int i=;i<=n;i++) rnk[g[i].pos]=i;
     for(int i=;i<=n;i++)
     {
         rt[i]=rt[i-];
         inst(rt[i],rnk[i],,n);
     }
     while(T--)
     {
         a=read(),b=read(),c=read();
         printf("%d\n", g[query(c,rt[a-],rt[b],,n)].val);
     }
 }