Obayanju

Array

• Two Sum
• Best Time to Buy and Sell Stock
• Contains Duplicate
• Product of Array Except Self
• Maximum Subarray
• Maximum Product Subarray
• Find Minimum in Rotated Sorted Array

Obayanju

def getInt():
    return int(input())

def getListOfInts():
    return list(map(int, input().split(' ')))

def main():
    t = getInt() 

main()

Obayanju

# Space comp = O(n) where n = number of numbers
class ProductList:
  def __init__(self):
    self.prefixProd = []

  # Time Comp = O(1) 
  def add(self, n):
    prefixProd = self.prefixProd
    if n == 0:
      self.prefixProd = []

Obayanju

'''
You are given a snapshot of a queue of stocks that have changing prices coming in from a stream. Remove the outdated stocks from the queue.

Example:
$ snapshot = [
  { sym: ‘GME’, cost: 280 },
  { sym: ‘PYPL’, cost: 234 },
  { sym: ‘AMZN’, cost: 3206 },
  { sym: ‘AMZN’, cost: 3213 },
  { sym: ‘GME’, cost: 325 }

Obayanju

def count_bills(bills, amount):
    result = 0
    bills.reverse()
    for bill in bills:
        result += amount//bill
        amount %= bill
    return result

def count_bills2(bills, amount):
    dp = [0] + [float('inf')]*amount

Obayanju

'''
Koko loves to eat bananas.  There are N piles of bananas, the i-th pile has piles[i] bananas.  The guards have gone and will come back in H hours.

Koko can decide her bananas-per-hour eating speed of K.  Each hour, she chooses some pile of bananas, and eats K bananas from that pile.  If the pile has less than K bananas, she eats all of them instead, and won't eat any more bananas during this hour.

Koko likes to eat slowly, but still wants to finish eating all the bananas before the guards come back.

Return the minimum integer K such that she can eat all the bananas within H hours.

 https://leetcode.com/problems/koko-eating-bananas/

Obayanju

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

• Stores data elements based on an sequential, most commonly 0 based, index.
• Based on tuples from set theory.

Obayanju

function Planet() {
  // ....
}

// create a new prototype object
Planet.prototype = {/* .. */};

let mars = new Planet();
mars.constructor === Planet; // false
mars.constructor === Object; // true

Obayanju

function Planet() {
  // ....
}

Planet.prototype.constructor === Planet; // true

let mars = new Planet();
mars.constructor === Planet; // true

Obayanju

function Planet() {
  // ....
}

let mars = new Planet();