@@ -23,61 +23,89 @@ const isRootNode = index => {
2323 return index === 0 ;
2424} ;
2525
26- 2726const isEmpty = ( element ) => {
2827 return element === undefined || element === null ;
2928}
3029
31- 3230const heapifyUp = ( array , index ) => {
31+ index = index || array . length - 1 ;
3332 const parentIndex = getParentIndex ( index ) ;
3433 if ( parentIndex >= 0 && array [ index ] > array [ parentIndex ] ) {
3534 swap ( array , index , parentIndex ) ;
3635 heapifyUp ( array , parentIndex ) ;
3736 }
3837}
3938
40- 4139const heapifyDown = ( array , index ) => {
4240 const element = array [ index ] ;
4341 const leftChildIndex = getLeftChildIndex ( index ) ;
4442 const rightChildIndex = getRightChildIndex ( index ) ;
4543 const leftChildElement = array [ leftChildIndex ] ;
4644 const rightChildElement = array [ rightChildIndex ] ;
45+ let maxIndex = null ;
46+ 4747 if ( isEmpty ( leftChildElement ) && isEmpty ( rightChildElement ) ) {
4848 return ;
4949 }
50+ 51+ if ( isEmpty ( leftChildElement ) ) {
52+ maxIndex = rightChildIndex ;
53+ }
54+ else if ( isEmpty ( rightChildElement ) ) {
55+ maxIndex = leftChildIndex ;
56+ }
5057 else {
51- if ( element < leftChildElement || element < rightChildElement ) {
52- const maxIndex = getMaxIndex ( array , leftChildIndex , rightChildIndex ) ;
53- swap ( array , index , maxIndex ) ;
54- heapifyDown ( array , maxIndex ) ;
55- }
58+ maxIndex = getMaxIndex ( array , leftChildIndex , rightChildIndex ) ;
5659 }
57- }
5860
61+ if ( element <= leftChildElement || element < rightChildElement ) {
62+ swap ( array , index , maxIndex ) ;
63+ heapifyDown ( array , maxIndex ) ;
64+ }
65+ 66+ }
5967
60- // delete the root node
6168const deleteNode = ( array ) => {
6269 swap ( array , 0 , array . length - 1 ) ;
6370 array . length = array . length - 1 ;
64- heapifyDown ( array , 0 )
71+ heapifyDown ( array , 0 ) ;
6572}
6673
6774const insertNode = ( array , value ) => {
6875 array . push ( value ) ;
69- heapifyUp ( array , array . length - 1 )
76+ heapifyUp ( array )
7077}
7178
7279const buildHeap = ( array , element ) => {
73- for ( let index = array . length - 1 ; index > =array . length / 2 ; index -- ) {
80+ for ( let index = Math . floor ( array . length / 2 ) ; index < =array . length - 1 ; index ++ ) {
7481 heapifyUp ( array , index ) ;
7582 }
7683
84+ // for (let index = Math.floor(array.length / 2); index >= 0; index--) {
85+ // heapifyDown(array, index);
86+ // }
7787}
7888
79- // const heap = [0, 1, 2, 3, 4, 5, 6];
80- // buildHeap(heap);
89+ 90+ const heapSort = ( array ) => {
91+ buildHeap ( array ) ;
92+ const sortedArray = [ ] ;
93+ while ( array . length > 0 ) {
94+ swap ( array , 0 , array . length - 1 ) ;
95+ sortedArray [ array . length - 1 ] = array [ array . length - 1 ] ;
96+ array . length = array . length - 1 ;
97+ heapifyDown ( array , 0 ) ;
98+ }
99+ 100+ array . push ( ...sortedArray ) ;
101+ sortedArray . length = 0 ;
102+ }
103+ 104+ // Arr[ N/2+1 ] to Arr[ N ] are the leaf nodes
105+ 106+ const array = [ 4 , 1 , 5 , 3 , 0 , 2 , 6 ] ;
107+ // heapSort(array);
108+ // buildHeap(array);
81109// const heap = [6, 4, 5, 3, 1, 0, 2];
82110// deleteNode(array);
83111// const heap = [];
@@ -89,12 +117,12 @@ const buildHeap = (array, element) => {
89117// insertNode(heap, 2, heap.length);
90118// insertNode(heap, 3, heap.length);
91119// console.log(heap);
92- // deleteNode(heap );
93- // deleteNode(heap );
94- // deleteNode(heap );
95- // console.log(heap );
96- // insertNode(heap , 2);
97- // insertNode(heap , 3);
98- // console.log(heap );
120+ // deleteNode(array );
121+ // deleteNode(array );
122+ // deleteNode(array );
123+ // console.log(array );
124+ // insertNode(array , 2);
125+ // insertNode(array , 3);
126+ console . log ( array ) ;
99127
100128
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