414B - Mashmokh and ACM - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;

#define int long long int
const int mod = 1e9 + 7;

int fun(int i, int k, vector<vector<int>> &dp, int total)
{
    if (k <= 0)
        return 1;

    if (dp[i][k] != -1)
        return dp[i][k];

    int sum = 0;
    for (int j = i; j <= total; j += i)
        sum += fun(j, k - 1, dp, total) % mod;
        
    return dp[i][k] = sum % mod;
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    vector<vector<int>> dp(2005, vector<int>(2005, -1));

    int n, k;
    cin >> n >> k;
    int total = n;
    cout << fun(1, k, dp, n);

    return 0;
}