

## Phone Screen

### Coding Round:
1. [65. Valid Number](https://leetcode.com/problems/valid-number/description/) - variation: do not consider “e/E” (exponent) strings as valid.
2. [695 Max Area of Island](https://leetcode.com/problems/max-area-of-island/description/) - variation: can not update the input - follow up: what are some practical limitations of this approach?

## Onsite

### Coding Round 1
1. Variation of [1004. Max Consecutive Ones III](https://leetcode.com/problems/max-consecutive-ones-iii/description/)
0 => Work Days
1 => Holiday
K => PTO

2. [1249. Minimum Remove to Make Valid Parentheses](https://leetcode.com/problems/minimum-remove-to-make-valid-parentheses/?envType=company&envId=facebook&favoriteSlug=facebook-thirty-days)

### Coding Round 2
1. [680. Valid Palindrome II](https://leetcode.com/problems/valid-palindrome-ii/description/)
    - Follow up: [1216. Valid Palindrome III](https://leetcode.com/problems/valid-palindrome-iii/description/)

2. [543. Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/description/?envType=company&envId=facebook&favoriteSlug=facebook-thirty-days)
    - Follow up: Diameter of N-ary Tree

### System Design
- Track Trending Hashtags (Top K Heavy Hitters)
    - Accuracy in tracking
    - K = 30 hashtags
    - Window = 12 hours
    - Scale: 2B DAU posting 100 M posts per day

### System Design Follow Up
- Design Messenger

## Status: PASSED


Phone ScreenCoding Round:
65. Valid Number - variation: do not consider “e/E” (exponent) strings as valid.
695 Max Area of Island - variation: can not update the input - follow up: what are some practical limitations of this approach?
OnsiteCoding Ro