関連ワード:  binary tree and threaded binary tree    binary tree and threaded binary tree difference    extended binary tree and threaded binary tree    binary tree vs threaded binary tree    difference between binary search tree and threaded binary tree    single threaded binary tree and double threaded binary tree    convert binary tree to threaded binary tree    convert binary tree into threaded binary tree    traversing threaded binary tree    difference between threaded binary tree and normal binary tree