Introduction
Problem statement
We are given an array having N distinct positive integers and a range [L, R]. Our task is to find all the elements in the range [L, R] that are coprime with all given array elements in the given array.
Let us revisit what are coprime numbers:
Coprime Numbers
 A pair of numbers are coprime if they do not have any common factor other than 1.
 There should be at least 2 numbers to form a set of coprime numbers. For example, (5, 6), (7, 9), (3, 7) etc.
Sample test cases
Example 1:
Input: a[] = { 5, 6, 8, 9, 11, 2, 18 }, L = 5, R = 10
Output: 7
Explanation
{7} is the only element in the range of L to R, which is coprime with all given array elements
Example 2:
Input: a[] = { 7, 9, 4, 11, 22, 13, 16, 8, 24 }, L = 4, R = 18
Output: 17 5
Explanation
{17,5} are the elements in the range of L to R, which are coprime with all given array elements
Approach
The idea is simple, calculate all the divisors for every array element and store it in a container. Traverse the container and for every divisor, remove all the multiples of it from the range [L, R]. Finally, print all the numbers after removing every divisor's multiples from the range [L, R].
We will use an unordered set to store all the divisors for every array element.
Steps of algorithm
 Store all the divisors for every array element in an unordered set and remove 1 from it, say DIV.
 Store all the numbers in the range [L, R] in another unordered set, say NUMS.
 Traverse the unordered set DIV and for each element, remove all the multiples of that element from the NUMS if it is present in NUMS.

Print all the numbers present in NUMS, which are coprime with all given array elements.
Letâ€™s understand the above approach with an example:
Given array = { 7, 9, 4, 11, 22, 13, 16, 8, 24 }, L = 4, R = 18
Steps:
 Store all the divisors for every element in DIV and remove 1 from DIV.
Divisors of 7 = {1, 7}
Divisors of 9 = {1, 3, 9}
Divisors of 4 = {1, 2, 4}
Divisors of 11 = {1, 11}
Divisors of 22 = {1, 2, 11, 22}
Divisors of 13 = {1, 13}
Divisors of 16 = {1, 2, 4, 8, 16}
Divisors of 8 = {1, 2, 4, 8}
Divisors of 24 = {1, 2, 3, 4, 6, 8, 12, 24}
DIV = { 6, 12, 8, 3, 9, 7, 24, 4, 2, 13, 11, 22, 16 }
 Store all the numbers from L to R in NUMS.
NUMS = { 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 }

Remove all the multiples of every element in DIV from NUMS.
Element in DIV (N)  All multiples of N <= R 
6  6, 12, 18 
12  12 
8  8, 16 
3  3, 6, 9, 12, 15, 18 
9  9, 18 
7  7, 14 
24  
4  4, 8, 12, 16 
2  2, 4, 6, 8, 10, 12, 14, 16, 18 
13  13 
11  11 
22  
16  16 
After removing the multiples, NUMS = { 5, 17 }

Print all the numbers present in NUMS, which are coprime with all given array elements.