/practice-for-week-05-array-long-practice

Primary LanguageJavaScript

Array Practice Problems

Implement the following problems. The skeleton code is provided to you in array-practice.js

While doing the problems, make sure to recite out loud and write in comments the time complexities of any Array operations you use. Evaluate the time and space complexities of each problem after you finish them. Ask yourself if the problem's time and space complexities can be further optimized.

Find Minimum

Given an Array of numbers, return the smallest number in the array. Do this in O(n) Time.

Example:

const arr = [7, 5, 2, 3, 4, 1]; 
findMinimum(arr); // => 1

Running Sum of Array

Given an array of numbers, return the running sum of its elements.

Example:

const arr = [1,2,3,4]; 
runningSum(arr); // => [1,3,6,10]

Even Number of Characters

Given an array of strings, return the number of strings with an even number of characters

Example:

const arr = ['ab', 'abc', 'a', 'abcd']; 
evenNumOfChars(arr); // => 2

How many numbers smaller than current number

Given an array of numbers, return a new array containing the number of elements smaller than the current element at each position.

Example:

const arr = [8,1,2,2,3];
smallerThanCurr(arr); // => [4,0,1,1,3]

Two Sum

Given an array of numbers and a target sum, your function should return a boolean value (true or false) if there are two elements in the array that add up to the target value.

Example:

const arr = [4, 2, 3, 6, 9]; 
twoSum(arr, 10); // => True

const arr2 = [4, 2, 3, 6, 9];
twoSum(arr2, 16); // => False

Find Second Largest

Given an array of numbers, return the second largest number in the array.

Example:

const arr = [4, 2, 3, 6, 8];
secondLargest(arr); // => 6

Shuffle The Array

Given an array, return an array containing those elements in random order.

Your function should return a new array and NOT mutate the original.

Hint: Look up Math.random() on MDN.

Example:

const arr = [2, 5, 1, 3, 4, 7];
shuffle(arr); // => [2, 3, 5, 4, 1, 7]