Count all subsequences having product less than K in C++

In this tutorial, we will be discussing a program to find the number of sub sequences having product less than K.

For this we will be provided with non-negative array and a value k. Our task is to find all the subsequences in the array having product less than k.

Example

 Live Demo

#include <bits/stdc++.h> using namespace std; //counting subsequences with product //less than k int count_sub(vector<int> &arr, int k){    int n = arr.size();    int dp[k + 1][n + 1];    memset(dp, 0, sizeof(dp));    for (int i = 1; i <= k; i++) {       for (int j = 1; j <= n; j++) {          dp[i][j] = dp[i][j - 1];          if (arr[j - 1] <= i && arr[j - 1] > 0)             dp[i][j] += dp[i/arr[j-1]][j-1] + 1;       }    }    return dp[k][n]; } int main(){    vector<int> A;    A.push_back(1);    A.push_back(2);    A.push_back(3);    A.push_back(4);    int k = 10;    cout << count_sub(A, k) << endl; }

Output

11