Question 1. You are given an array. Sort by pairs, but if the array length is odd, dont touch the final number.
Example: Input [5,4,2,3,7] Output [4,5,2,3,7]

Question 2. LC 3034. Number of Subarrays That Match a Pattern I

Question 3. I do not remember

Question 4. LC 2021, Brightest Position on Street