DS & Algorithms

Question 1

What is an algorithm?

Answer 1

An algorithm is just the steps you take to solve a problem

A step-by-step procedure that defines a set of instructions that must be carried out in a specific order to produce the desired result

An algorithm is just a function

Question 2

When worrying about real data, what 2 things do you have to worry about?

Answer 2

Space and time

Question 3

What is Big-O notation?

Answer 3

It mathematically describes the complexity of an algorithm in terms of time and SPCE

Question 4

Name the 4 big O time complexities

Answer 4

Quadratic O(n^2), linear O(n), logarithmic O(log n), constant time O(1)

Question 5

O(1)

Answer 5

For all inputs to our algorithm there is and will always be only one operation required
- Order 1
- Constant Time

Question 6

O(1) Example

Answer 6

const nums = [1,2,3,4,5]
const firstNumber = nums[0]

No matter how many inputs are located in num, there will only ever be one operation needed!

Question 7

O(N)

Answer 7

For all inputs to our algorithm there will be one operation per input
- Order N
- Linear
- Linear Scaling

Question 8

O(N) Example

Answer 8

const nums = [1,2,3,4,5]
let sum = 0;
for (let num of nums) {
sum += num
}

Question 9

What is space complexity?

Answer 9

How much memory is used

Question 10

What is time complexity?

Answer 10

How many primitive operations are executed