Language: C++

#ifdef LOCAL
#include <cstdio>
#include <vector>
#include <algorithm>
#include <iostream>
#include <cstring>
#else
#include <bits/stdc++.h>
#endif
using namespace std ;

typedef long long ll ;
#define rep(i , n ) for ( int i =0; i < n ; i++)
#define _sort(arg) sort(begin(arg), end(arg))
#define MOD 1000000007
#define pb push_back
#define DEBUG(x) cout << #x << ": " << x << endl;

class UnionFind {
private:
	unsigned size_; 
	std::vector<unsigned> par, rank;
public:
	UnionFind() : size_(0), par(std::vector<unsigned>()), rank(std::vector<unsigned>()) {};
	UnionFind(unsigned size__) : size_(size__) {
		par.resize(size_); rank.resize(size_);
		for (unsigned i = 0; i < size_; i++) par[i] = i, rank[i] = 0;
	}
	unsigned size() { return size_; }
	//unsigned root(unsigned x) { return par[x] == x ? x : par[x] = root(par[x]); }
	unsigned root(unsigned x)
	{
		while(par[x] != x)
		{
			par[x] = par[par[x]];
			x = par[x];
		}
		return x;
	}
	bool same(unsigned x, unsigned y) { return root(x) == root(y); }
	void unite(unsigned x, unsigned y) {
		x = root(x), y = root(y);
		if (x == y) return;
		if (rank[x] < rank[y]) par[x] = y;
		else if (rank[x] == rank[y]) par[y] = x, rank[x]++;
		else par[y] = x;
	}
	bool operator==(const UnionFind &u) { return par == u.par; }
	bool operator!=(const UnionFind &u) { return par != u.par; }
};

/*
maybe sth wrong 
got wa in one problem
*/
ll modpow(ll a, ll b)
{
	if (b == 0)
	{
		return 1;
	}

	if (b % 2)
	{
		return a * modpow(a, b-1) % MOD;
	}
	else
	{
		ll halfB = b / 2;
		ll half = modpow(a, halfB);
		return half * half % MOD;
	}
}

ll calcComb(ll n, ll m)
{
	if (m > n-m)
	{
		return calcComb(n, n-m);
	}

	ll ansMul = 1;
	ll ansDiv = 1;

	rep(i, m)
	{
		ansMul *= (n-i);
		ansDiv *= (i+1);
		ansMul %= MOD;
		ansDiv %= MOD;
	}

	return ansMul * modpow(ansDiv, MOD - 2) % MOD;
}

__attribute__((constructor))
void initial()
{
	cin.tie(NULL);
	ios::sync_with_stdio(false);
}


int main()
{
	int n, k;
	
	cin >> n >> k;
	if (k == 0)
	{
		cout << n * n << endl;
		return 0;
	}

	ll ans = 0;

	rep(i, n+1)
	{
		if (i-1 >= k)
		{
			ans += (n / i) * (i - k);
			ans += max((n % i)- k + 1, 0ll);
		}
	}

	cout << ans << endl;
	
	return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:122:35: error: no matching function for call to 'max(int, long long int)'
  122 |                         ans += max((n % i)- k + 1, 0ll);
      |                                ~~~^~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:8:
/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:122:35: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'long long int')
  122 |                         ans += max((n % i)- k + 1, 0ll);
      |                                ~~~^~~~~~~~~~~~~~~~~~~~~
/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:
/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:122:35: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
  122 |                         ans += max((n % i)- k + 1, 0ll);
      |                                ~~~^~~~~~~~~~~~~~~~~~~~~