HackerRank Interview Prep Kit Problem 1: Sales by Match Walkthrough

Описание: Hello, my name is Brian Dyck, I am a full-time software engineer and a Computer Science graduate walking through HackerRank problems for new and old programmers alike. My goal is to help programmers build up skills and not just see the solutions to problems, but to learn how to think through the problems. Many new videos to come, so stay tuned!

Todays problem: Sales by Match
Description:
Alex works at a clothing store. There is a large pile of socks that must be paired by color for sale. Given an array of integers representing the color of each sock, determine how many pairs of socks with matching colors there are.

For example, there are n = 7 socks with colors ar = [1, 2, 1, 2, 1, 3, 2]. There is one pair of color 1 and one of color 2. There are three odd socks left, one of each color. The number of pairs is 2.