Algorithm

We store a binary heap in an array because it simplifies the way we access parent and child nodes.
for a node at index i

Since we're checking whether the array represents a min heap, we need to ensure that every parent node is less than or equal to both of its children. That's the key rule for min heaps. We don’t have to check every element in the array. Leaf nodes don’t have children, so they can’t violate the heap property. In an array of size n, leaf nodes start from index n/2, so the only nodes we actually need to check are from index 0 to n/2 - 1. These are the non-leaf nodes. For each of these, we compute their children’s indices and compare values. If any parent node is found to be greater than one of its children, we can immediately return false because the heap rule is broken. If all the parent nodes satisfy the condition, then the array is a valid min heap.

Iterate over all non-leaf nodes.
For each index:
- Compute the index of the left child.
- Compute the index of the right child.
- If the left child exists and its value is less than the current node’s value, return false.
- If the right child exists and its value is less than the current node’s value, return false.
If the loop finishes without any violations, return true.