Merge pull request #3 from iramirezc/chapter-1

Chapter 1: Fundamentals

Author: Isaac Ramírez

README.md

@@ -4,7 +4,7 @@ Personal notes and JavaScript code for the book Algorithms (4th edition) by Robe
 
 ## Chapters' Notes
 
-* [Chapter 1. Fundamentals](/docs/chapter-1.md)
+* [Chapter 1. Fundamentals](/docs/chapter-1.notes.md)
 * Chapter 2. Sorting
 * Chapter 3. Searching
 * Chapter 4. Graphs
@@ -14,11 +14,66 @@ Personal notes and JavaScript code for the book Algorithms (4th edition) by Robe
 ## Standard Libraries for JavaScript
 
 * [In](/src/libs/in/in.js)
-* StdDraw
+* StdDraw (*not implemented*)
 * [StdIn](/src/libs/std-in/std-in.js)
 * [StdOut](/src/libs/std-out/std-out.js)
 * [StdRandom](/src/libs/std-random/std-random.js)
 
 ## Benchmarks
 
-* [linear-vs-binary-search](/src/benchmarks/searching/linear-vs-binary-search.js)
+* [Linear Search vs. Binary Search](/src/benchmarks/searching/linear-vs-binary-search.js)
+
+## Algorithms & Data Structures
+
+_For a list similar to the book site see this [algorithms list](/docs/algorithms-list.md)._
+
+### Chapter 1. Fundamentals
+
+**Algorithms:**
+
+* [Euclid's - p. 4](/src/algorithms/euclidean/euclidean.js)
+* [BinarySearch - p. 47](/src/algorithms/binary-search/binary-search.js)
+* [LinearSearch - p. 48](/src/algorithms/linear-search/linear-search.js)
+* [Dijkstra's Two-Stack: Expression Evaluation - p. 129](/src/algorithms/dijkstra-two-stack/dijkstra-two-stack.js)
+* [ThreeSum - p. 173](/src/algorithms/three-sum/three-sum.js)
+* [TwoSumFast - p. 189](/src/algorithms/two-sum-fast/two-sum-fast.js)
+* [ThreeSumFast - p. 190](/src/algorithms/three-sum-fast/three-sum-fast.js)
+* [QuickFindUF - p. 221](/src/algorithms/union-find/union-find.js)
+* [QuickUnionUF - p. 224](/src/algorithms/union-find-quick/union-find-quick.js)
+* [WeightedQuickUnionUF - p. 228](/src/algorithms/union-find-weighted/union-find-weighted.js)
+
+**ADTs:**
+
+* [BasicDate - p. 79](/src/adts/basic-date/basic-date.js)
+* [SmallDate - p. 79](/src/adts/small-date/small-date.js)
+* [Transaction - p. 79](/src/adts/transaction/transaction.js)
+* [Counter - p. 85](/src/adts/counter/counter.js)
+* [Accumulator - p. 93](/src/adts/accumulator/accumulator.js)
+* [FixedCapacityStack - p. 135](/src/adts/fixed-capacity-stack/fixed-capacity-stack.js)
+* [ResizingArrayStack - p. 141](/src/adts/resizable-array-stack/resizable-array-stack.js)
+* [Node - p. 142](/src/adts/node/node.js)
+* [Stack - p. 149](/src/adts/stack/stack.js)
+* [Queue - p. 151](/src/adts/queue/queue.js)
+* [Bag - p. 155](/src/adts/bag/bag.js)
+* [StopWatch - p. 175](/src/adts/stop-watch/stop-watch.js)
+
+### Chapter 2. Sorting
+
+**Algorithms:**
+
+> TODO
+
+**ADTs:**
+
+> TODO
+
+## Exercise Solutions
+
+:warning: _Do **NOT** copy any of these solutions. These are for my reference only. You should have attempted to solve any of these exercises by your own after at least a few days before even trying to look for the solution. Finally, my solutions can be wrong too._
+
+* [Chapter 1. Fundamentals](/src/exercises/index.md)
+* Chapter 2. Sorting
+* Chapter 3. Searching
+* Chapter 4. Graphs
+* Chapter 5. Strings
+* Chapter 6. Context

docs/algorithms-list.md

@@ -0,0 +1,46 @@
+# Algorithms (4th Edition)
+
+## List of Algorithms and Abstract Data Types
+
+This is the extracted list from the book site [Java Algorithms & Clients](https://algs4.cs.princeton.edu/code/).
+
+Every algorithm or ADT has a link pointing to the original Java implementation and my JavaScript implementation.
+
+### Chapter 1. Fundamentals
+
+* Binary Search | [js](/src/algorithms/binary-search/binary-search.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/BinarySearch.java.html) |
+* RandomSeq | [js](/src/examples/test-clients/random-seq.client.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/RandomSeq.java.html) |
+* Average | [js](/src/examples/test-clients/average.client.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Average.java.html) |
+* Cat | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Cat.java.html) |
+* Knuth | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Knuth.java.html) |
+* Counter | [js](/src/adts/counter/counter.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Counter.java.html) |
+* StaticSETofInts | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/StaticSETofInts.java.html) |
+* AllowList | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Allowlist.java.html) |
+* Vector | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Vector.java.html) |
+* Date | [js](/src/adts/basic-date/basic-date.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Date.java.html) |
+* Transaction | [js](/src/adts/transaction/transaction.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Transaction.java.html) |
+* Point2D | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Point2D.java.html) |
+* RectHV | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/RectHV.java.html) |
+* Interval1D | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Interval1D.java.html) |
+* Interval2D | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Interval2D.java.html) |
+* Accumulator | [js](/src/adts/accumulator/accumulator.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Accumulator.java.html) |
+* ResizingArrayStack | [js](/src/adts/resizable-array-stack/resizable-array-stack.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/ResizingArrayStack.java.html) |
+* LinkedStack | [js](/src/adts/stack/stack.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/LinkedStack.java.html) |
+* Stack | [js](/src/adts/stack/stack.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Stack.java.html) |
+* ResizingArrayQueue | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/ResizingArrayQueue.java.html) |
+* LinkedQueue | [js](/src/adts/queue/queue.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/LinkedQueue.java.html) |
+* Queue | [js](/src/adts/queue/queue.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Queue.java.html) |
+* ResizingArrayBag | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/ResizingArrayBag.java.html) |
+* LinkedBag | [js](/src/adts/bag/bag.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/LinkedBag.java.html) |
+* Bag | [js](/src/adts/bag/bag.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Bag.java.html) |
+* Stopwatch | [js](/src/adts/stop-watch/stop-watch.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/Stopwatch.java.html) |
+* StopwatchCPU | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/StopwatchCPU.java.html) |
+* LinearRegression | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/LinearRegression.java.html) |
+* ThreeSum | [js](/src/algorithms/three-sum/three-sum.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/ThreeSum.java.html) |
+* ThreeSumFast | [js](/src/algorithms/three-sum-fast/three-sum-fast.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/ThreeSumFast.java.html) |
+* DoublingTest | [js](/src/examples/experiments/doubling-test.experiment.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/DoublingTest.java.html) |
+* DoublingRatio | [js](/src/examples/experiments/doubling-ratio.experiment.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/DoublingRatio.java.html) |
+* QuickFindUF | [js](/src/algorithms/union-find/union-find.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/QuickFindUF.java.html) |
+* QuickUnionUF | [js](/src/algorithms/union-find-quick/union-find-quick.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/QuickUnionUF.java.html) |
+* WeightedQuickUnionUF | [js](/src/algorithms/union-find-weighted/union-find-weighted.js) | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/WeightedQuickUnionUF.java.html) |
+* UF | js | [java](https://algs4.cs.princeton.edu/code/edu/princeton/cs/algs4/UF.java.html) |

docs/chapter-1.md renamed to docs/chapter-1.notes.md

@@ -2,20 +2,6 @@
 
 ## Chapter 1. Fundamentals
 
-### Algorithms
-
-* [Euclid's - Algorithm - p. 4](/src/algorithms/euclidean/euclidean.js)
-* [BinarySearch - Algorithm - p.47](/src/algorithms/binary-search/binary-search.js)
-* [LinearSearch - Algorithm - p.48](/src/algorithms/linear-search/linear-search.js)
-
-### Examples & Code Snippets
-
-* [StdRandom - TestClient - p. 32](/src/examples/test-clients/std-random.client.js)
-* [RandomSeq - TestClient - p. 37](/src/examples/test-clients/random-seq.client.js)
-* [Average - TestClient - p. 39](/src/examples/test-clients/average.client.js)
-* [BinarySearch - TestClient - p.47](/src/examples/test-clients/binary-search.client.js)
-* [LinearSearch - TestClient - p.48](/src/examples/test-clients/linear-search.client.js)
-
 ### Key Concepts
 
 #### Algorithm
@@ -85,3 +71,24 @@
 #### Data Abstraction
 
 > Extends encapsulation and reuse to allow defining non-primitive data types, supporting Object-Oriented programming.
+
+#### Data Structures
+
+> Two ways of representing object collections:
+>
+> * Arrays aka *Sequential Allocation*
+> * Linked Lists aka *Linked Allocation*
+
+#### The Scientific Method
+
+> * Observe
+> * Hypothesize
+> * Predict
+> * Verify
+> * Validate
+
+#### Analysis of Algorithms
+
+> _Premature optimization is the root of all evil_ - C. A. R. Hoare
+>
+> _Premature optimization is the root of all evil (or at least most of it) in programming_ - Knuth

docs/ex-1.1.x.js renamed to docs/samples/ex-1.1.x.js

@@ -71,7 +71,7 @@ Client.main(process.argv.slice(2))
 
 ### Exercise Answer
 
-### [Exercise 1.1.x](./ex-1.1.x.js)
+### [Exercise 1.1.x](./samples/ex-1.1.x.js)
 
 :pencil2: **Answer**
 

docs/templates.md renamed to docs/samples/templates.md

@@ -21,6 +21,7 @@
       "describe",
       "it",
       "expect",
+      "beforeAll",
       "beforeEach",
       "afterEach",
       "TestCase"

docs/test.client.js renamed to docs/samples/test.client.js

@@ -0,0 +1,54 @@
+/**
+ * ArrayIterator
+ * @classdesc Iterable interface for Array elements
+ * @abstract
+ * @see p. 135 (This is my custom implementation), 141
+ */
+class ArrayIterator {
+  constructor (array, n) {
+    this._current = 0
+    this._a = [...array]
+    this._n = n
+
+    Object.seal(this)
+  }
+
+  /**
+   * Returns if there are
+   * more elements in the Iterator.
+   */
+  hasNext () {
+    return this._current < this._n
+  }
+
+  /**
+   * Is best not to modify Data Structures
+   * when iterating.
+   * @see p. 139
+   */
+  remove () {
+    /* do nothing */
+  }
+
+  /**
+   * Returns an object implementing the Iterator protocol.
+   * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol
+   * @returns {object} iterator protocol
+   */
+  next () {
+    if (this.hasNext()) {
+      const item = this._a[this._current++]
+
+      return {
+        value: item,
+        done: false
+      }
+    } else {
+      return {
+        done: true
+      }
+    }
+  }
+}
+
+module.exports = ArrayIterator

package.json

@@ -0,0 +1,88 @@
+const ArrayIterator = require('./array-iterator')
+
+describe('Unit Tests: Abstract ArrayIterator Interface', () => {
+  describe('instance', () => {
+    beforeEach(() => {
+      this.array = [1, 2]
+      this.n = 2
+      this.iterator = new ArrayIterator(this.array, this.n)
+    })
+
+    describe('when initialized:', () => {
+      it('should have a prop `_current` equal to `0`', () => {
+        expect(this.iterator._current).toBe(0)
+      })
+
+      it('should have a prop `_a` equal to the array provided', () => {
+        expect(this.iterator._a).toEqual(this.array)
+        expect(this.iterator._a).not.toBe(this.array)
+      })
+
+      it('should have a prop `_n` equal to the n provided', () => {
+        expect(this.iterator._n).toEqual(this.n)
+      })
+
+      it('should not be extensible', () => {
+        const expectedProps = ['_current', '_a', '_n']
+
+        this.iterator.newProp = null
+
+        const actualProps = Object.getOwnPropertyNames(this.iterator)
+        expect(actualProps).toEqual(expectedProps)
+        expect(this.iterator.newProp).toBeUndefined()
+      })
+    })
+
+    describe('hasNext() method', () => {
+      it('should return false when _current is 0', () => {
+        this.iterator = new ArrayIterator([], 0)
+
+        const result = this.iterator.hasNext()
+
+        expect(result).toBeFalse()
+      })
+
+      it('should return true when there is an element', () => {
+        const result = this.iterator.hasNext()
+
+        expect(result).toBeTrue()
+      })
+
+      it('should return false when there are no more elements to iterate', () => {
+        this.iterator._current = this.iterator._n
+
+        const result = this.iterator.hasNext()
+
+        expect(result).toBeFalse()
+      })
+    })
+
+    describe('next() method', () => {
+      it('should return an object with the item value of the _current element', () => {
+        const result = this.iterator.next()
+
+        expect(result).toEqual({
+          value: this.array[0],
+          done: false
+        })
+      })
+
+      it('should increment _current on each call to next()', () => {
+        this.iterator.next()
+
+        expect(this.iterator._current).toBe(1)
+
+        this.iterator.next()
+
+        expect(this.iterator._current).toBe(2)
+      })
+
+      it('should return an object with `done` false when there are no more elements', () => {
+        this.iterator.next()
+        this.iterator.next()
+
+        expect(this.iterator.next()).toEqual({ done: true })
+      })
+    })
+  })
+})

src/abstracts/array-iterator/array-iterator.js

@@ -0,0 +1,5 @@
+module.exports = {
+  ArrayIterator: require('./array-iterator/array-iterator'),
+  Iterator: require('./iterator/iterator'),
+  ReversedArrayIterator: require('./reversed-array-iterator/reversed-array-iterator')
+}

src/abstracts/array-iterator/array-iterator.spec.js

@@ -0,0 +1,54 @@
+/**
+ * Iterator
+ * @classdesc Iterable interface for Node elements
+ * @abstract
+ * @see p. 155
+ */
+class Iterator {
+  constructor (element = null) {
+    this._current = element
+
+    Object.seal(this)
+  }
+
+  /**
+   * Returns if there are
+   * more elements in the Iterator.
+   */
+  hasNext () {
+    return this._current !== null
+  }
+
+  /**
+   * Is best not to modify Data Structures
+   * when iterating.
+   * @see p. 139
+   */
+  remove () {
+    /* do nothing */
+  }
+
+  /**
+   * Returns an object implementing the Iterator protocol.
+   * https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#The_iterator_protocol
+   * @returns {object} iterator protocol
+   */
+  next () {
+    if (this.hasNext()) {
+      const item = this._current._item
+
+      this._current = this._current._next
+
+      return {
+        value: item,
+        done: false
+      }
+    } else {
+      return {
+        done: true
+      }
+    }
+  }
+}
+
+module.exports = Iterator