In graph theory, a k-ary tree is a rooted tree in which each node has no more than k children. It is also sometimes known as a k-way tree, an N-ary tree, or an M-ary tree.
A binary tree is the special case where k=2.
A full k-ary tree is a k-ary tree where within each level every node has either 0 or k children. A perfect k-ary tree is a k-ary tree in which all leaf nodes are at the same depth.[1]
For a k-ary tree with height h, the upper bound for the maximum number of leaves is . The total number of nodes is , while the height h is