A binary tree $$T$$ has $$20$$ leaves. The number of nodes in $$T$$ having two children is _______________.

Consider a complete binary tree where the left and the right sub-trees of the root are max-heaps. The lower bound for the number of operations to convert the tree to a heap is

Consider the following rooted tree with the vertex labelled P as the root The order in which the nodes are visited during an in-order traversal of the tree is

Consider a rooted n node binary tree represented using pointers. The best upper bound on the time required to determine the number of subtrees having exactly 4 nodes O(n^a Log^bn ). Then the value of a + 10b is _________