public void increaseKey(int index, int key){
		if(index >= size)
			System.out.println("Invalid index");
		else if(maxHeap[index] >= key)
			System.out.println("New key is not greater than current key.");
		else{
			maxHeap[index] = key;
			int parent = (index - 1)/2;
			int temp;
			while(parent >= 0  && maxHeap[index] > maxHeap[parent]){
				temp = maxHeap[index];
				maxHeap[index] = maxHeap[parent];
				maxHeap[parent] = temp;
				index = parent;
				parent = (index - 1)/2;
			}
		}
	}