CC-2 : Implement Min Heap

Below fully running code can be copied and run on Eclipse or other Java IDEs. Refer the classname in code below. If the class name below is "A", save the code below to a file named A.java before running it. Be sure to try your own test cases to enhance your understanding ! You can also tweak the code to optimize or add enhancements and custom features.

public class HeapMin {
 
private int[] minHeap=new int[20];
private int currSize;
	
public boolean insert(int num) {
	if (currSize >= minHeap.length) {return false;}
	minHeap[currSize]=num;
	currSize++;
	int idx=currSize-1;
	int parentIdx=(idx-1)/2;
	while ((idx > 0)&& (minHeap[idx] < minHeap[parentIdx])){
		int temp=minHeap[idx];
		minHeap[idx]=minHeap[parentIdx];
		minHeap[parentIdx]=temp;
		idx=parentIdx;
		parentIdx=(idx-1)/2;
	}
	
	return true;
}

public int delete(int val) {
	if (currSize == 0) {return Integer.MIN_VALUE;}
	int idx=-1;
	for (int i=0;i < currSize; i++) {
		if (minHeap[i]==val) {
			idx=i;			
		}
	}
	if (idx==-1) {return Integer.MIN_VALUE;}
	minHeap[idx]=minHeap[currSize-1];
	minHeap[currSize-1]=0;
	currSize--;
	updateHeap(idx);
	return idx;
}

public int deleteTop() {
	if (currSize == 0) {return Integer.MIN_VALUE;}
	int top=minHeap[0];
	minHeap[0]=minHeap[currSize-1];
	minHeap[currSize-1]=0;
	currSize--;
	updateHeap(0);
	
	return top;
}

public void updateHeap(int idx) {
	int parentIdx=idx;
	int leftChildIdx= 2*idx+1;
	int rightChildIdx=2*idx+2;
	if ((leftChildIdx < currSize) && (minHeap[leftChildIdx] < minHeap [parentIdx])) {
		parentIdx=leftChildIdx;
	}
	if ((rightChildIdx < currSize) && (minHeap[rightChildIdx] < minHeap [parentIdx])) {
		parentIdx=rightChildIdx;
	}
	if (parentIdx != idx) {
		int temp=minHeap[idx];
		minHeap[idx]=minHeap[parentIdx];
		minHeap[parentIdx]=temp;
		updateHeap(parentIdx);
	}
}
	
public int getCurrSize() {
	return currSize;
}
public void setCurrSize(int currSize) {
	this.currSize = currSize;
}

public int[] getMinHeap() {
	return minHeap;
}
public void setMinHeap(int[] minHeap) {
	this.minHeap = minHeap;
}

public static void printArray(int[] intArray, String label) throws Exception {
	// Case 1: The input Array is null !!
	if (intArray == null) { System.out.println("\n\n Input Array was null !! \n"); return; }
	// Case 2: Print input Array by index (first to last)
	System.out.println();
	System.out.println("**********************************************************************");
	System.out.print(label+" : \n");
	int arrayIndex=0;
	for (arrayIndex=0; arrayIndex < intArray.length; arrayIndex++) {
			System.out.print("["+arrayIndex+"] = "+intArray[arrayIndex]+"\n");
	} 
	System.out.println();
	System.out.println("**********************************************************************");
	System.out.println();
	Thread.sleep(2000);
	return;
}

public static void main(String[] args) {
	/***********************
	 Test cases given below:
	 **********************/
	int[] retVal;
	try {
	HeapMin hp=new HeapMin();
	hp.insert(43);
	hp.insert(92);
	hp.insert(21);
	hp.insert(44);
	hp.insert(12);
	hp.insert(67);
	hp.insert(55);
	retVal=hp.getMinHeap();
	printArray(retVal, "Min Heap");
	hp.deleteTop();
	retVal=hp.getMinHeap();
	printArray(retVal, "Min Heap after top deletion");
	hp.delete(43);
	retVal=hp.getMinHeap();
	printArray(retVal, "Min Heap after 43 deletion");	
			
	}catch (Exception exception) {
		System.out.print("Exception: "+ exception);
		exception.printStackTrace();
	}
		
}
}