Language: C++

#include <iostream>
#include <algorithm>
#include <cmath>
#include <limits>
#include <vector>
#include <cstdio>
#include <bits/stdc++.h>
#include <set>
#include <map>
#include <stdio.h>
#include <stack>
#include <queue>
#include <deque>
#include <numeric>
#include <bits/stdc++.h>
#include <utility>
#include <iomanip>

#define ALL(obj) (obj).begin(), (obj).end()
#define FOR(i,a,b) for(int i = (a); i < (b); i++)
#define RFOR(i,a,b) for(int i = (a); (b) <= i; i--)
#define REP(i,n) for(int i = 0; i < (n); i++)
#define RREP(i,n) for(int i = n; n <= i; i--)
#define ABS(a) ((a < 0) ? ((-1)*(a)) : (a))
#define elif else if
#define MOD 1000000007
#define INF (1<<29)

using namespace std;

#define ld long double
#define ll long long

map <int ,int> mpa,mpb;
typedef pair<ll, ll> P;
priority_queue<P, vector<P>, greater<P>> pque;

int main(){
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  ll N,K;
  cin >> N >> K;
  ll ans=0;
  ll cnt;
  if(K==0){
    cout << N*N << endl;
    return 0;
  }
  for(ll i=K+1;i<=N;i++){
    // cnt=0;
    ans+=(i-K)*(N/i);
    //cout << ans << " " << cnt << endl;
    ll r=N-(N/i)*i+1;
    ans+=max(0,r-K);
    //cout << ans << " " << cnt << endl;
  }
  cout << ans << endl;
  return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:54:13: error: no matching function for call to 'max(int, long long int)'
   54 |     ans+=max(0,r-K);
      |          ~~~^~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:54:13: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
   54 |     ans+=max(0,r-K);
      |          ~~~^~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:2:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:54:13: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   54 |     ans+=max(0,r-K);
      |          ~~~^~~~~~~