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In computer science, a ternary search tree is a type of trie (sometimes called a ''prefix tree'') where nodes are arranged in a manner similar to a binary search tree, but with up to three children rather than the binary tree's limit of two. Like other prefix trees, a ternary search tree can be used as an associative map structure with the ability for incremental string search. However, ternary search trees are more space efficient compared to standard prefix trees, at the cost of speed. Common applications for ternary search trees include spell-checking and auto-completion. ==Description== Each node of a ternary search tree stores a single character, an object (or a pointer to an object depending on implementation), and pointers to its three children conventionally named ''equal kid'', ''lo kid'' and ''hi kid'', which can also be referred respectively as ''middle (child)'', ''lower (child)'' and ''higher (child)''. A node may also have a pointer to its parent node as well as an indicator as to whether or not the node marks the end of a word.〔 The ''lo kid'' pointer must point to a node whose character value is ''less than the current node''. The ''hi kid'' pointer must point to a node whose character is ''greater than the current node''.〔The ''equal kid'' points to the next character in the word. The figure below shows a ternary search tree with the strings "as", "at", "cup", "cute", "he", "i" and "us": c / | \ a u h | | | \ t t e u / / | / | s p e i s As with other trie data structures, each node in a ternary search tree represents a prefix of the stored strings. All strings in the middle subtree of a node start with that prefix. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ternary search tree」の詳細全文を読む スポンサード リンク
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