How to check if array is a min heap?

Question

I have the following array. How can I check whether the array containing n elements is a min heap?

Answer 1

Since your index starts from 1, (index 0 contains 0 - why?), you can determine the index of a given node's children as follows:

• Let the index of the given node be i
• Index of i's left child: 2i
• Index of i's right child: 2i + 1

Thus for each node, you can easily check that both children are greater than the node itself.