# Delete Node in a BST Problem

1. Search for a node to remove.
2. If the node is…

# Largest Component Size by Common Factor Problem

• There are `A.length` nodes, labelled `A` to `A[A.length - 1];`
• There is an edge between `A[i]` and `A[j]` if and only if `A[i]` and `A[j]` share a common factor greater than 1.
`Input: [4,6,15,35]Output: 4`

# Pancake Sorting Problem

• Choose an integer `k` where `0 <= k < A.length`.
• Reverse the sub-array `A[0...k]`.

# Implement Rand10() Using Rand7() Problem

`Input: 1Output: `
`Input: 2Output: [8,4]`
`Input: 3Output: [8,1,10]`
1. `rand7` is predefined.
2. Each testcase has one argument: `n`, the number of times that `rand10` is called.
1. What is the expected value for the number of calls to `rand7()` function?
2. Could you minimize the number of calls to `rand7()`?

# Fizz Buzz Problem

`n = 15,Return:[    "1",    "2",    "Fizz",    "4",    "Buzz",    "Fizz",    "7",    "8",    "Fizz",    "Buzz",    "11",    "Fizz",    "13",    "14",    "FizzBuzz"]`

• a…

# Sum of Left Leaves Problem

`3   / \  9  20    /  \   15   7There are two left leaves in the binary tree, with values 9 and 15 respectively. Return 24.`

# Stream of Characters Problem

• `StreamChecker(words)`: Constructor, init the data structure with the given words.
• `query(letter)`: returns true if and only if for some `k >= 1`, the last `k` characters queried (in order from oldest to newest, including this letter just queried) spell one of the words in…

# 31 days Challenge — Day 22 