Can depend on:

• data structures that grow in some proportion to input
• a call stack that grows in some proportion to input

Rather than comparing each element to every other element, keep track of relevant max/mins as you go

• Benefits:
  • Saves time compared to nested loops
• Used in:
  • Best Time to Buy and Sell Stock

Can be for loop with two variables:

for (let i=0, j=arr.length-1; i <= j; i++, j--){
    // ...
}

Or while loop with left/right:

let left = 0
let right = 0

while (left < right) {
    // ...
    left ++
    right --
}

• Benefits:
  • Saves space compared to creating a new array to track values
• Used in:
  • Valid Palindromes

Can use regex, .replace() (or equivalent)

• Benefits:
  • Saves time and space compared to creating a new entity
• Used in:
  • Valid Palindromes

Works well for fractal things (e.g. trees) — that is, things whose zoomed-in pieces look similar to the zoomed-out whole

• Used in:
  • Invert Binary Tree

Uses recursion to reach the lowest node of one branch of a tree, then progresses to subsequent branches

• Used in:
  • Invert Binary Tree

Uses a queue data structure (First in, first out):