With a preorder traversal, a heap that produces its elements in sorted order is that which is represented by the vector $(1,2,5,3,4,6,7)$. There does not exist a heap for which an inorder traversal produces the keys in sorted order. This is because in a heap the parent is always less than all of its children or greater than all of its children. The heap represented by $(7,3,6,1,2,4,5)$ is an example of one which produces its keys in sorted order during a postorder traversal.