@@ -79,4 +79,109 @@ public void percolateDown(int i){
7979
8080 percolateDown (max ); //recursive call untill all nodes are correct location.
8181 }
82+ 83+ //Deleting an element from the heap, we only need to delete the element from the root
84+ /*
85+ * After deleting the root element, copy the last element of the heap and delete that last element.
86+ * After replacing the last element, tree may not satisfy heap property and hence we need to make it a heap again
87+ * by calling percolate down function
88+ */
89+ 90+ int DeleteMax (){
91+ if (this .count ==0 ){
92+ return -1 ;
93+ }
94+ 95+ int data = this .array [0 ];
96+ this .array [0 ]= this .array [this .count -1 ];
97+ this .count --; //reduces heap size
98+ percolateDown (0 );
99+ return data ;
100+ }
101+ 102+ //Inserting an element is simliar to heapifying and deleting, but instead of percolating down we use percolate up function
103+ /*
104+ * increase the heap size
105+ * keep new element at end of the heap
106+ * heapify the element from bottom to top (root)
107+ */
108+ public void Insert (int data ){
109+ int i ;
110+ if (this .count ==this .capacity ){
111+ resizeHeap ();
112+ }
113+ 114+ this .count ++; //increasing the heap size to hold this new item
115+ i = this .count -1 ;
116+ 117+ while (i >=0 && data > this .array [(i -2 )/2 ]){
118+ this .array [i ] =this .array [(i -1 )/2 ];
119+ i = i -1 /2 ;
120+ }
121+ 122+ this .array [i ]=data ;
123+ }
124+ 125+ public void resizeHeap (){
126+ int [] array_old = new int [this .capacity ];
127+ System .arraycopy (this .array ,0 ,array_old , this .count -1 , capacity );
128+ this .array = new int [this .capacity *2 ];
129+ if (this .array == null ){
130+ System .out .println ("Memory error" );
131+ return ;
132+ }
133+ 134+ for (int i =0 ; i < this .capacity ; i ++){
135+ this .array [i ]=array_old [i ];
136+ }
137+ 138+ this .capacity *=2 ;
139+ array_old =null ;
140+ }
141+ 142+ public void DestroyHeap (){
143+ this .count =0 ;
144+ this .array =null ;
145+ }
146+ 147+ //in case we already have an array we have to heapify the array so it can become a heap
148+ /*
149+ *
150+ */
151+ 152+ public void BuildHeap (Heap h , int [] A , int n ){
153+ if (h == null ){
154+ return ;
155+ }
156+ 157+ while (n > this .capacity ){
158+ h .resizeHeap ();
159+ }
160+ 161+ for (int i =0 ; i < n ; i ++){
162+ h .array [i ] = A [i ];
163+ }
164+ 165+ this .count =n ;
166+ for (int i = (n -1 )/2 ; i >=0 ; i --){
167+ h .percolateDown (i );
168+ }
169+ }
170+ 171+ 172+ //HEAP SORT -> INSERTS ALL ELEMENTS FROM UNSORTED ARRAY INTO HEAP, THEN REMOVES THE ROOT ELEMENTS UNTIL THE HEAP IS EMPTY
173+ public void heapSort (int [] A , int n ){
174+ Heap h = new Heap (n ,0 );
175+ int old_size = h .count ;
176+ int temp ;
177+ 178+ for (int i = n -1 ; i >0 ; i --){ //h.array[0] is the largest element
179+ temp =h .array [0 ];
180+ h .array [0 ]= h .array [h .count -1 ];
181+ h .count --;
182+ h .percolateDown (0 );
183+ }
184+ 185+ h .count = old_size ;
186+ }
82187}
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