Related Articles

# Find elements of an array which are divisible by N using STL in C++

• Last Updated : 18 Dec, 2019

Given an array and an integer N, find elements which are divisible by N, using STL in C++

Examples:

```Input: a[] = {1, 2, 3, 4, 5, 10}, N = 2
Output: 3
Explanation:
As 2, 4, and 10 are divisible by 2
Therefore the output is 3

Input:a[] = {4, 3, 5, 9, 11}, N = 5
Output: 1
Explanation:
As only 5 is divisible by 5
Therefore the output is 3
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: This can be achieved using count_if() method in C++

Syntax:

```count_if(lower_bound, upper_bound, function)
```

where function takes the element of given sequence one by one as a parameter and returns a boolean value on the basis of condition specified in that function.

In this case, the function will be:

```bool isDiv(int i)
{
if (i % N == 0)
return true;
else
return false;
}
```

Below is the implementation of the above approach:

 `// C++ simple program to``// find elements which are``// divisible by N`` ` `#include ``using` `namespace` `std;`` ` `int` `N;`` ` `// Function to check``// if the element is divisible by N``bool` `isDiv(``int` `i)``{``    ``if` `(i % N == 0)``        ``return` `true``;``    ``else``        ``return` `false``;``}`` ` `// Driver code``int` `main()``{``    ``int` `a[] = { 1, 2, 6, 3, 4, 5 };``    ``N = 2;`` ` `    ``int` `n = ``sizeof``(a) / ``sizeof``(a);`` ` `    ``int` `count = count_if(a, a + n, isDiv);`` ` `    ``cout << ``"Elements divisible by "``         ``<< N << ``": "` `<< count;`` ` `    ``return` `0;``}`
Output:
```Elements divisible by 2: 3
```
Want to learn from the best curated videos and practice problems, check out the C++ Foundation Course for Basic to Advanced C++ and C++ STL Course for the language and STL. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.
My Personal Notes arrow_drop_up