Sock Merchant – HackerRank Problem Solution


John works at a clothing store. He has a large pile of socks that he must pair 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.


10 20 20 10 10 30 50 10 20



Here is actual problem HackerRank.


Solution Logic:

  • Sort the array and store into temp array
  • Iterate the array while temp array does not remove its all item
    • Check if first element of an array is equals (=) to second element array increase the count and remove the starting two elements from temp array.
    • If first element of an array is not equals (=) to second element the remove only first element from an array.

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