Problem Brief
Find Doubles
INTERNOA
Given a list of N integers, not necessarily unique, find all elements of the list for which there exists exactly one element of the list which is twice that number. The integers range from 0 to 1000. The list has no more than 100,000 elements.
Your code should find the appropriate values and print them to STDOUT in sorted order.
1Example 1
Input
numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 8]
Output
[0, 1, 2, 3]
Explanation
8 is 4*2, but 8 is present twice, 0 is its own double, so it's part of the result.
2Example 2
Input
numbers = [7, 17, 11, 1, 23]
Output
[]
Explanation
Nothing is exactly twice another element.
3Example 3
Input
numbers = [1, 1, 2]
Output
[1, 1]
Explanation
1 and 1 both have their double 2 present, and 2 is present in the list only once.