Title: Single Number
Url: Leetcode (level: Easy)
Note: XOR, also known as "exclusive or", compares two binary numbers bitwise. If both bits are the same, XOR outputs 0. If the bits are different, XOR outputs 1.
  Url: Leetcode (level: Easy)
Note: XOR, also known as "exclusive or", compares two binary numbers bitwise. If both bits are the same, XOR outputs 0. If the bits are different, XOR outputs 1.
Title: 771. Jewels and Stones
Url: https://leetcode.com/problems/jewels-and-stones/
  Url: https://leetcode.com/problems/jewels-and-stones/
Title:1486. XOR Operation in an Array
Url:https://leetcode.com/problems/xor-operation-in-an-array/
  Url:https://leetcode.com/problems/xor-operation-in-an-array/
Title: 1614. Maximum Nesting Depth of the Parentheses
Url: https://leetcode.com/problems/maximum-nesting-depth-of-the-parentheses/
  Url: https://leetcode.com/problems/maximum-nesting-depth-of-the-parentheses/
Title: Implement strStr()
Url: https://leetcode.com/problems/implement-strstr/submissions/
  Url: https://leetcode.com/problems/implement-strstr/submissions/
Title: Reverse Words in a String III
Url: https://leetcode.com/problems/reverse-words-in-a-string-iii/
  Url: https://leetcode.com/problems/reverse-words-in-a-string-iii/