@@ -13,8 +13,6 @@ export default class BinarySearchTree {
1313 }
1414
1515 public insert ( value : number ) {
16- // TODO: Insert value into BST
17- 1816 // If empty tree, create root
1917 if ( this . root === null ) {
2018 this . root = new BNode ( value ) ;
@@ -50,8 +48,35 @@ export default class BinarySearchTree {
5048 }
5149
5250 public lookup ( value : number ) {
53- // TODO: Find value in BST
54- console . log ( "Lookup not implemented" ) ;
51+ let currentNode : BNode ;
52+ 53+ if ( ! ! this . root ) {
54+ currentNode = this . root ;
55+ } else {
56+ return null ;
57+ }
58+ 59+ while ( true ) {
60+ // We found our value!
61+ if ( value === currentNode . getValue ( ) ) {
62+ return currentNode ;
63+ }
64+ 65+ 66+ if ( value < currentNode . getValue ( ) ) { // Value is smaller than current node
67+ if ( ! ! currentNode . getLeft ( ) ) { // If left child exists
68+ currentNode = currentNode . getLeft ( ) ; // Move into left child
69+ continue ;
70+ }
71+ return null ; // No left child, value DNE
72+ } else { // Value is greater than current node
73+ if ( ! ! currentNode . getRight ( ) ) { // If right child exists
74+ currentNode = currentNode . getRight ( ) ; // Move into right child
75+ continue ;
76+ }
77+ return null ; // No right child, value DNE
78+ }
79+ }
5580 }
5681
5782 public remove ( value : number ) {
@@ -88,7 +113,16 @@ if (import.meta.main) {
88113 tree . insert ( 170 ) ;
89114 tree . insert ( 15 ) ;
90115 tree . insert ( 1 ) ;
91- console . log ( JSON . stringify ( traverseFrom ( tree . getRoot ( ) ) ) ) ;
116+ console . log ( 'Tree: ' , JSON . stringify ( traverseFrom ( tree . getRoot ( ) ) ) ) ;
117+ printNode ( tree , 4 ) ;
118+ printNode ( tree , 17 ) ;
119+ printNode ( tree , 40 ) ;
120+ printNode ( tree , 170 ) ;
92121
93122 // RUN: deno run Data-Structures/Trees/BinarySearchTree.ts
123+ }
124+ 125+ function printNode ( tree : BinarySearchTree , value : number ) : void {
126+ const requestedNode = tree . lookup ( value ) ;
127+ console . log ( 'Find' , value + ':' , ! ! requestedNode ? JSON . stringify ( requestedNode ) : 'Node not found.' ) ;
94128}
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