Challenge 1: Single Number
In this lesson, every element appears twice except one element. Try to come up with a process to solve this. Use your XOR skills to achieve this.
Introduction
In this question, every element appears twice except one element, which is our answer.
Let’s see how to achieve this using the XOR operator.
Problem statement
We need to write a program that finds the element that is not repeated.
Input: nums = { 4, 1, 2, 9, 1, 4, 2 }
Output: 9
Explanation: Except for 9, all elements are repeated.
Assume n is non-negative.
Hint: Use the ^ operator to achieve this.
Solution
We solve this using naive, and then we move to solve it in a more optimal way.
Brute force
This is a naive approach. We traverse the entire array twice to achieve this, which is not optimal.
Algorithm
Iterate the elements using two for loops and find the one that is not repeating.
Complexity analysis
Time Complexity: O()
Space Complexity: ...