chore(lab): add new exercises and fix comment:wq

Author: amejiarosario

lab/exercises/10-mixed/trie-wildcard-search.js

@@ -0,0 +1,54 @@
+/**
+ * Your WordDictionary object will be instantiated and called as such:
+ * var obj = new WordDictionary()
+ * obj.addWord(word)
+ * var param_2 = obj.search(word)
+ */
+class WordDictionary {
+  children = {};
+  isWord = false;
+  /**
+   * Initialize your data structure here.
+   */
+  constructor() {
+  }
+
+  /**
+   * Adds a word into the data structure.
+   * @param {string} word
+   * @return {void}
+   */
+  addWord (word) {
+    let curr = this;
+
+    for (let char of word) {
+      if (!curr.children[char]) curr.children[char] = new WordDictionary();
+      curr = curr.children[char];
+    }
+
+    curr.isWord = true;
+  }
+
+  /**
+   * Returns if the word is in the data structure.
+   * A word could contain the dot character '.' to represent any one letter.
+   * @param {string} word
+   * @return {boolean}
+   */
+  search (word, curr = this, index = 0) {
+    if (index > word.length) return true; // e.g. final '.'
+    for (let [i, char] of [...word.slice(index)].entries()) {
+      if (char === '.') {
+        for (let child of Object.keys(curr.children)) {
+          if (this.search(word, curr.children[child], i + 1)) return true;
+        }
+      }
+      else if (!curr || !curr.children[char]) return false;
+      curr = curr.children[char];
+    }
+
+    return curr.isWord;
+  }
+}
+
+module.exports = WordDictionary;

lab/exercises/10-mixed/trie-wildcard-search.spec.js

@@ -0,0 +1,47 @@
+const WordDictionary = require('./trie-wildcard-search');
+
+describe('WordDictionary', () => {
+  let wd;
+
+  beforeEach(() => {
+    wd = new WordDictionary();
+  });
+
+  describe('should find exact matches', () => {
+    beforeEach(() => {
+      wd.addWord('bad');
+      wd.addWord('mad');
+    });
+
+    it('should find match', () => {
+      expect(wd.search('bad')).toEqual(true);
+      expect(wd.search('mad')).toEqual(true);
+    });
+
+    it('should be false for partial match', () => {
+      expect(wd.search('ba')).toEqual(false);
+    });
+
+    it('should be false for NO match', () => {
+      expect(wd.search('dad')).toEqual(false);
+    });
+  });
+
+  describe('should find wildcard matches', () => {
+    beforeEach(() => {
+      wd.addWord('bad');
+    });
+
+    it('should work with 1 wildcard', () => {
+      expect(wd.search('.ad')).toEqual(true);
+    });
+
+    it('should work with 1 wildcard not match', () => {
+      expect(wd.search('.ax')).toEqual(false);
+    });
+
+    it('should work with 2 wildcard', () => {
+      expect(wd.search('..d')).toEqual(true);
+    });
+  });
+});

src/data-structures/graphs/graph.js

@@ -250,12 +250,7 @@ class Graph {
   }
 }
 
-Graph.UNDIRECTED = Symbol('undirected graph'); // one-way edges
-Graph.DIRECTED = Symbol('directed graph'); // two-ways edges
+Graph.UNDIRECTED = Symbol('directed graph'); // two-ways edges
+Graph.DIRECTED = Symbol('undirected graph'); // one-way edges
 
 module.exports = Graph;
-
-/*
- * https://repl.it/@amejiarosario/graphpy
- * http://www.pythontutor.com/visualize.html#mode=edit - https://goo.gl/Xp7Zpm
- */