Coding Challenge #1 – Sum of multiples

Here is a little coding challenge to try.

The objective is to find the sum of multiples within a given range.

For example assume that given multiples are 4, 5 and 7. The upper limit is 20 (excluding). Multiples of 4 within 20 are 4, 8, 12 and 16. Then multiples of 5 within 20 are 5, 10 and 15. The multiples of 7 within 20 are 7 and 14. The objective is to find the sum of all those numbers.

The upper limit and the number of multiples can be vary from problem to problem.

Solution in Cpp

#include <iostream>

using namespace std;

int isMult(int mult[], int n, int length);

int main () {
int no_of_mult = 2;
int multiSet[no_of_mult] = {3, 5};
int upper_limit = 10;

int sum = 0;
for (int i=0; i &lt; upper_limit; i++){
sum = sum + isMult(multiSet, i, no_of_mult);
}
cout &lt;&lt; "Sum = " &lt;&lt; sum;
}

int isMult(int mult[], int n, int length){
for(int i =0; i &lt; length; i++){
int r = n % mult[i];
if(r == 0){
return n;
}
}
return 0;
}

Try it online http://tpcg.io/ujmQDD