Commit 5914947

committed

update: TrieNode, insert() in Trie

1 parent 72f5ba5 commit 5914947Copy full SHA for 5914947

File tree

+59

-0

lines changed

+59

-0

lines changed

Lines changed: 20 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,20 @@`
	`1`	`+class TrieNode {`
	`2`	`+ constructor(char) {`
	`3`	`+ this.char = char;`
	`4`	`+ this.children = [];`
	`5`	`+ this.isEndOfWord = false;`
	`6`	`+`
	`7`	`+ // mark all the alphabets as null`
	`8`	`+ for (let i = 0; i < 26; i += 1) this.children[i] = null;`
	`9`	`+ }`
	`10`	`+`
	`11`	`+ markAsLeaf() {`
	`12`	`+ this.isEndOfWord = true;`
	`13`	`+ }`
	`14`	`+`
	`15`	`+ unmarkAsLeaf() {`
	`16`	`+ this.isEndOfWord = false;`
	`17`	`+ }`
	`18`	`+}`
	`19`	`+`
	`20`	`+module.exports = TrieNode;`

Lines changed: 39 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,39 @@`
	`1`	`+const Node = require('./Node');`
	`2`	`+`
	`3`	`+class Trie {`
	`4`	`+ constructor() {`
	`5`	`+ this.root = new Node('');`
	`6`	`+ }`
	`7`	`+`
	`8`	`+ insert(key) {`
	`9`	`+ if (!key) {`
	`10`	`+ return false;`
	`11`	`+ }`
	`12`	`+`
	`13`	`+ // convert to lower case`
	`14`	`+ // keys are basically words`
	`15`	`+ const word = key.toLowerCase();`
	`16`	`+ let currentNode = this.root;`
	`17`	`+`
	`18`	`+ for (let level = 0; level < word.length; level += 1) {`
	`19`	`+ const index = this.getIndexOfChar(word[level]);`
	`20`	`+ if (!currentNode.children[index]) {`
	`21`	`+ currentNode.children[index] = new Node(word[level]);`
	`22`	`+ }`
	`23`	`+ currentNode = currentNode.children[index];`
	`24`	`+ }`
	`25`	`+`
	`26`	`+ // when we are done with inserting all the character of the word,`
	`27`	`+ // mark the node as end leaf`
	`28`	`+ currentNode.markAsLeaf();`
	`29`	`+ return true;`
	`30`	`+ }`
	`31`	`+`
	`32`	`+ // helper to get the index of a character`
	`33`	`+ // eslint-disable-next-line class-methods-use-this`
	`34`	`+ getIndexOfChar(char) {`
	`35`	`+ return char.charCodeAt(0) - 'a'.charCodeAt(0);`
	`36`	`+ }`
	`37`	`+}`
	`38`	`+`
	`39`	`+module.exports = Trie;`

Comments

(0)