Update 642-design-search-autocomplete-system.js

Author: everthis

642-design-search-autocomplete-system.js

@@ -105,3 +105,154 @@ Trie.prototype.stringsStartingWith = function (prefix) {
   traverse(curr, prefix)
   return results
 }
+
+// another
+
+class TrieNode {
+  constructor() {
+    this.children = new Map()
+    this.counts = new Map()
+    this.isWord = false
+  }
+}
+
+class Pair {
+  constructor(s, c) {
+    this.str = s
+    this.cnt = c
+  }
+}
+
+/**
+ * @param {string[]} sentences
+ * @param {number[]} times
+ */
+const AutocompleteSystem = function (sentences, times) {
+  this.root = new TrieNode()
+  this.prefix = ''
+  for (let i = 0, n = sentences.length; i < n; i++) {
+    this.add(sentences[i], times[i])
+  }
+}
+
+AutocompleteSystem.prototype.add = function (str, cnt) {
+  let cur = this.root
+  for (const ch of str) {
+    let next = cur.children.get(ch)
+    if (next == null) {
+      next = new TrieNode()
+      cur.children.set(ch, next)
+    }
+    cur = next
+    cur.counts.set(str, (cur.counts.get(str) || 0) + cnt)
+  }
+  cur.isWord = true
+}
+
+/**
+ * @param {character} c
+ * @return {string[]}
+ */
+AutocompleteSystem.prototype.input = function (c) {
+  if (c === '#') {
+    this.add(this.prefix, 1)
+    this.prefix = ''
+    return []
+  }
+  this.prefix += c
+  let cur = this.root
+  for (const ch of this.prefix) {
+    const next = cur.children.get(ch)
+    if (next == null) {
+      return []
+    }
+    cur = next
+  }
+  const pq = new PriorityQueue((a, b) =>
+    a.cnt === b.cnt ? a.str.localeCompare(b.str) < 0 : a.cnt > b.cnt
+  )
+
+  for(const s of cur.counts.keys()) {
+    pq.push(new Pair(s, cur.counts.get(s)))
+  }
+  const res = []
+  for(let i = 0; i < 3 && pq.size(); i++) {
+    res.push(pq.pop().str)
+  }
+
+  return res
+}
+
+/**
+ * Your AutocompleteSystem object will be instantiated and called as such:
+ * var obj = new AutocompleteSystem(sentences, times)
+ * var param_1 = obj.input(c)
+ */
+
+class PriorityQueue {
+  constructor(comparator = (a, b) => a > b) {
+    this.heap = []
+    this.top = 0
+    this.comparator = comparator
+  }
+  size() {
+    return this.heap.length
+  }
+  isEmpty() {
+    return this.size() === 0
+  }
+  peek() {
+    return this.heap[this.top]
+  }
+  push(...values) {
+    values.forEach((value) => {
+      this.heap.push(value)
+      this.siftUp()
+    })
+    return this.size()
+  }
+  pop() {
+    const poppedValue = this.peek()
+    const bottom = this.size() - 1
+    if (bottom > this.top) {
+      this.swap(this.top, bottom)
+    }
+    this.heap.pop()
+    this.siftDown()
+    return poppedValue
+  }
+  replace(value) {
+    const replacedValue = this.peek()
+    this.heap[this.top] = value
+    this.siftDown()
+    return replacedValue
+  }
+
+  parent = (i) => ((i + 1) >>> 1) - 1
+  left = (i) => (i << 1) + 1
+  right = (i) => (i + 1) << 1
+  greater = (i, j) => this.comparator(this.heap[i], this.heap[j])
+  swap = (i, j) => ([this.heap[i], this.heap[j]] = [this.heap[j], this.heap[i]])
+  siftUp = () => {
+    let node = this.size() - 1
+    while (node > this.top && this.greater(node, this.parent(node))) {
+      this.swap(node, this.parent(node))
+      node = this.parent(node)
+    }
+  }
+  siftDown = () => {
+    let node = this.top
+    while (
+      (this.left(node) < this.size() && this.greater(this.left(node), node)) ||
+      (this.right(node) < this.size() && this.greater(this.right(node), node))
+    ) {
+      let maxChild =
+        this.right(node) < this.size() &&
+        this.greater(this.right(node), this.left(node))
+          ? this.right(node)
+          : this.left(node)
+      this.swap(node, maxChild)
+      node = maxChild
+    }
+  }
+}