No-Category

Quick Select

http://www.cs.yale.edu/homes/aspnes/pinewiki/QuickSelect.html

Median of median https://en.wikipedia.org/wiki/Median_of_medians

• No. 215 Kth Largest Element in an Array

Graph

Should be in Data Structure. but not many leetcode problems.

• 310. Minimum Height Trees: remove leaves

Not solved

1. Cut Off Trees for Golf Event

Convex Hull

• No. 469 Convex Polygon(Check): Degree of corner is less than 180 degree

• No. 381: Insert Delete GetRandom O(1) - Duplicates allowed

Boring:

• 1. Self Dividing Numbers: check all

Many Cases:

• No. 65: Valid Number

• No. 8: String to Integer (atoi)

• No.13: Roman to Integer

  • Right from left

• No. 717: 1-bit and 2-bit Characters

• 54. Spiral Matrix

• 605. Can Place Flowers

Cannot Categorize

• No. 283: Move Zeros. (swap to save time)