#include<bits/stdc++.h>
using namespace std;
int x[8]={500000,250000,125000,62496,20832,3472,183,1};
int xhs(vector<int> x)
{
    int l=x.size();
    vector<int> a,b,c;map<int,int> mp;
    a.reserve(l*(l-1)/2),b.reserve(l*(l-1)/2);
    for(int i=0;i<l;i++)for(int j=i+1;j<l;j++)
        a.emplace_back(x[i]),b.emplace_back(x[j]);
    c=ask(a,b);for(int i:c)mp[i]++;
    for(auto [p,q]:mp)if(q==l)return p;
}
int richest(int N,int T,int S)
{
    if(N==1000)
    {
        vector<int> a;a.resize(N);
        iota(a.begin(),a.end(),0);
        return xhs(a);
    }
    if(N==1000000)
    {
        vector<int> a;a.resize(N);
        iota(a.begin(),a.end(),0);
        int n=N;
        for(int r=0;r<8;r++)
        {
            vector<int> b(n/x[r]),c(n/x[r]+1),t;
            t.reserve(x[r]);
            for(int i=0;i<x[r]-n%x[r];i++)
            {
                for(int j=0;j<n/x[r];j++)
                    b[j]=a[n/x[r]*i+j];
                t.emplace_back(xhs(b));
            }
            for(int i=0;i<n%x[r];i++)
            {
                for(int j=0;j<n/x[r]+1;j++)
                    c[j]=a[(x[r]-n%x[r])*(n/x[r])+(n/x[r]+1)*i+j];
                t.emplace_back(xhs(c));
            }
            a=t,n=x[r];
        }
        return a[0];
    }
}

answer.code: In function ‘int xhs(std::vector<int>)’:
answer.code:11:7: error: ‘ask’ was not declared in this scope
   11 |     c=ask(a,b);for(int i:c)mp[i]++;
      |       ^~~
answer.code:12:14: warning: structured bindings only available with ‘-std=c++17’ or ‘-std=gnu++17’ [-Wc++17-extensions]
   12 |     for(auto [p,q]:mp)if(q==l)return p;
      |              ^
answer.code:13:1: warning: control reaches end of non-void function [-Wreturn-type]
   13 | }
      | ^
answer.code: In function ‘int richest(int, int, int)’:
answer.code:47:1: warning: control reaches end of non-void function [-Wreturn-type]
   47 | }
      | ^