Tips

Use Set/Hashet for unique values https://leetcode.com/problems/contains-duplicate/
Use Math.max(int,int) to get the max number between a number and a calculation. https://leetcode.com/problems/best-time-to-buy-and-sell-stock/
Two pass are necessary to calculate the left and right products https://leetcode.com/problems/product-of-array-except-self/
A product invert the sign, the max becomes the min, and the min becomes the max: https://leetcode.com/problems/maximum-product-subarray/
Binary search exploit "sorted and rotated" structure. At every iteration, it divide the space by 2 using left or right. https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/

Sorting Algoritms