Tag: Python Counter

Teaching Kids Programming: Videos on Data Structures and Algorithms You are given an integer array nums. The unique elements of an array are the elements that appear exactly once …

Teaching Kids Programming: Videos on Data Structures and Algorithms Given a string s, return the first non-repeating character in it and return its index. If it does not exist, …

Teaching Kids Programming: Videos on Data Structures and Algorithms Given an array of integers arr, a lucky integer is an integer which has a frequency in the array equal …

Teaching Kids Programming: Videos on Data Structures and Algorithms Given a non-empty array of integers nums, every element appears twice except for one. Find that single one. Follow up: Could you …

You are given an integer array nums. The unique elements of an array are the elements that appear exactly once in the array. Return the sum of all the …