Create MaxHeap.js

Data-Structures/Heap/MaxHeap.js

@@ -0,0 +1,89 @@
+class MaxHeap {
+ constructor() {
+ this.heap = [];
+ }
+
+ insert(value) {
+ this.heap.push(value);
+ this.bubbleUp();
+ }
+
+ extractMax() {
+ if (this.isEmpty()) {
+ return null;
+ }
+
+ if (this.heap.length === 1) {
+ return this.heap.pop();
+ }
+
+ const max = this.heap[0];
+ this.heap[0] = this.heap.pop();
+ this.sinkDown(0);
+ return max;
+ }
+
+ isEmpty() {
+ return this.heap.length === 0;
+ }
+
+ peek() {
+ return this.isEmpty() ? null : this.heap[0];
+ }
+
+ bubbleUp() {
+ let index = this.heap.length - 1;
+
+ while (index > 0) {
+ const element = this.heap[index];
+ const parentIndex = Math.floor((index - 1) / 2);
+ const parent = this.heap[parentIndex];
+
+ if (element <= parent) {
+ break;
+ }
+
+ this.heap[index] = parent;
+ this.heap[parentIndex] = element;
+ index = parentIndex;
+ }
+ }
+
+ sinkDown(index) {
+ const leftChildIndex = 2 * index + 1;
+ const rightChildIndex = 2 * index + 2;
+ const length = this.heap.length;
+ let largest = index;
+
+ if (leftChildIndex < length && this.heap[leftChildIndex] > this.heap[largest]) {
+ largest = leftChildIndex;
+ }
+
+ if (rightChildIndex < length && this.heap[rightChildIndex] > this.heap[largest]) {
+ largest = rightChildIndex;
+ }
+
+ if (largest !== index) {
+ const temp = this.heap[index];
+ this.heap[index] = this.heap[largest];
+ this.heap[largest] = temp;
+ this.sinkDown(largest);
+ }
+ }
+}
+
+// Example usage:
+const maxHeap = new MaxHeap();
+
+maxHeap.insert(10);
+maxHeap.insert(5);
+maxHeap.insert(15);
+maxHeap.insert(3);
+maxHeap.insert(7);
+
+console.log("Max Heap:");
+console.log(maxHeap.heap);
+
+console.log("Extract Max:", maxHeap.extractMax()); // Should return 15
+console.log("Max Heap after extraction:");
+console.log(maxHeap.heap);