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208-Implement-Trie.kt
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208-Implement-Trie.kt
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class Trie() {
private class Node {
val nxt = Array(26) { null as Node? }
var end = false
}
private val root = Node()
fun insert(word: String) {
var cur = root
for (c in word) {
cur = cur.nxt[c - 'a'] ?: Node().also { cur.nxt[c - 'a'] = it }
}
cur.end = true
}
fun search(word: String): Boolean = internalSearch(word, prefix = false)
fun startsWith(prefix: String): Boolean = internalSearch(prefix, prefix = true)
private fun internalSearch(word: String, prefix: Boolean): Boolean {
var cur = root
for (c in word) {
cur = cur.nxt[c - 'a'] ?: return false
}
return cur.end || prefix
}
}
/**
* Your Trie object will be instantiated and called as such:
* var obj = Trie()
* obj.insert(word)
* var param_2 = obj.search(word)
* var param_3 = obj.startsWith(prefix)
*/