Ruby Toy

Find the most frequent integer

Given an array of integers (positive, negative, or 0), find the integer that occurs most frequently in that array (you might remember this as the mode from your middle school math class). The set of numbers won't necessarily be in order. If there is more than one number that appears most frequently, your algorithm should return nil.

Here are some examples:

• [1, 2, 1, 1,] should return 1
• [1, 2, 3, 4] should return nil
• [1, 1, 2, 3, 3] should return nil