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Commit b5a00dd

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feat(book:array): add solutions for interview questions
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‎.vscode/settings.json

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}
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[appendix]
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[[d-interview-questions-solutions]]
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== Interview Questions Solutions
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(((Interview Questions Solutions)))
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=== Solutions for Array Questions
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(((Interview Questions Solutions, Arrays)))
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==== Rotate Left
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include::content/part02/array.asc[tag=array-q-rotate-left]
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We are asked to rotate an array multiple times (`k`).
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One brute force solution, would be removing the first element and appending it to the end `k` times:
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include::interview-questions/rotate-array-left.js[tag=bruteForce]
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However, what would happen if the array is huge (millions of elements)?
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How efficient will be if `k` number is large (thousands)?
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When k is bigger than the array, it will loop back over and over again. We can avoid extra computation by calculating the final place using modulus.
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Here's the final solution:
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include::interview-questions/rotate-array-left.js[tag=description]
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include::interview-questions/rotate-array-left.js[tag=solution]
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It runs on `O(n^2)` while the brute force solution was doing `O(n^2 * k)`.
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==== Sum
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include::content/part02/array.asc[tag=array-sum]

‎book/ch02-git-basics-chapter.asc

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‎book/content/part02/array.asc

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.Fixed vs. Dynamic Size Arrays
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****
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Some programming languages have fixed size arrays like Java and C++. Fixed size arrays might be a hassle when your collection gets full, and you have to create a new one with a bigger size. For that, those programming languages also have built-in dynamic arrays: we have `vector` in C++ and `ArrayList` in Java. Dynamic programming languages like JavaScript, Ruby, and Python use dynamic arrays by default.
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Some programming languages have fixed size arrays like Java and C++.
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Fixed size arrays might be a hassle when your collection gets full, and you have to create a new one with a bigger size. For that, those programming languages also have built-in dynamic arrays: we have `vector` in C++ and `ArrayList` in Java. Dynamic programming languages like JavaScript, Ruby, and Python use dynamic arrays by default.
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****
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Arrays look like this:
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|===
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//end::table
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==== Array Exercises
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==== Interview Questions
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(((Interview Questions, Arrays)))
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// tag::array-q-rotate-left[]
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1) Implement an efficient algorithm that rotate an array `a` an `k` number of times.
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[source, javascript]
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----
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/**
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* Rotate an array left by k number of times.
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*
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* @example
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* rotateLeft([1,2,3], 1); // [2,3,1]
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* rotateLeft([1,2,3,4,5], 4); // [5,1,2,3,4]
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*
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* rotateLeft(Array(1e6).fill(1), 1e4); // <scale testing>
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*
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* @param a - The array
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* @param k - The number of times the array is rotated
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*/
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function rotateLeft(a, k) {
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// write you code and test with examples
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include::../../interview-questions/rotate-array-left.js[tag=description]
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// write you code here
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}
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----
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// end::array-q-rotate-left[]
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// tag::array-sum[]
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2) Implement an algorithm that takes two arrays of numbers and return a new array with the sum.
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[source, javascript]
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// write you code and test with examples
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}
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----
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// end::array-sum[]

‎book/content/preface.asc

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Your feedback is very welcome and valuable. Let us know what your thoughts about this book — what you like or ideas to make it better.
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To send us feedback, e-mail us at hello+dsajs@adrianmejia.com, send a tweet to https://twitter.com/iAmAdrianMejia[@iAmAdrianMejia], or using the hash tags `#dsaJS`, `#javascript` and `#algorithms`.
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To send us feedback, e-mail us at hello+dsajs@adrianmejia.com, send a tweet to https://twitter.com/iAmAdrianMejia[@iAmAdrianMejia], or using the hash tag `#dsaJS`.
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// tag::description[]
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/**
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* Rotate an array left by k number of times.
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*
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* @example
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* rotateLeft([1,2,3], 1); // [2,3,1]
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* rotateLeft([1,2,3,4,5], 4); // [5,1,2,3,4]
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*
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* rotateLeft(Array(1e6).fill(1), 1e4); // <scale testing>
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*
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* @param a - The array
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* @param k - The number of times the array is rotated
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*/
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function rotateLeft(a, k) {
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// end::description[]
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// tag::solution[]
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const moves = k % a.length;
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for (let i = 0; i < moves; i++) {
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a.push(a.shift());
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}
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return a;
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}
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// end::solution[]
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// tag::bruteForce[]
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function rotateLeftBruteForce(a, k) {
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for (let i = 0; i < k; i++) {
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a.push(a.shift());
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}
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return a;
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}
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// end::bruteForce[]
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module.exports = { rotateLeft, rotateLeftBruteForce };
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const { rotateLeft, rotateLeftBruteForce } = require('./rotate-array-left');
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describe('Rotate Left', () => {
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describe('when data is small', () => {
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it('should work with 1', () => {
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expect(rotateLeft([1, 2, 3], 1)).toEqual([2, 3, 1]);
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});
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it('should work with 4', () => {
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expect(rotateLeft([1, 2, 3, 4, 5], 4)).toEqual([5, 1, 2, 3, 4]);
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});
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});
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describe('when data is large', () => {
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it('', () => {
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});
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});
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});

‎lab/exercises/01-arrays/rotate-array-left.js

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‎notes.md

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console.log('bar');
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/* eslint-enable no-alert */
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```
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# Asciidoctor Manual
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https://asciidoctor.org/docs/user-manual/

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