Merge pull request #2624 from aadil42/patch-66

Create 1268-search-suggestions-system.js

Author: aakhtar3

Diff for: javascript/1268-search-suggestions-system.js

@@ -0,0 +1,157 @@
+/**
+ * Binary Search
+ * 
+ * Time O(n*log(n) + m*n) | Space O(m)
+ * https://leetcode.com/problems/search-suggestions-system/description/
+ * @param {string[]} products
+ * @param {string} searchWord
+ * @return {string[][]}
+ */
+var suggestedProducts = function(products, searchWord) {
+
+    products.sort((product1, product2) => {
+        if(product1 < product2) {
+            return -1;
+        }
+        if(product2 < product1) {
+            return 1;
+        }
+        if(product1 === product2) {
+            return 0;
+        }
+    });
+
+    const result = [];
+    let left = 0;
+    let right = products.length - 1;
+    for(let i = 0;  i < searchWord.length; i++) {
+        let char = searchWord[i];
+        
+        while(left <= right && (products[left].length - 1 < i || products[left][i] !== char)) {
+            left++;
+        }
+        while(left <= right && (products[right].length - 1 < i || products[right][i] !== char)) {
+            right--;
+        }
+
+        const subResult = [];
+        const len = Math.min(right - left + 1, 3);
+        for(let j = 0; j < len; j++) {
+            subResult.push(products[left+j]);
+        }
+        result.push(subResult);
+    }
+
+    return result;
+};
+
+/**
+ * DFS - Trie
+ * Time O(N * M) | Space O(N)
+ * https://leetcode.com/problems/search-suggestions-system/
+ * @param {string[]} products
+ * @param {string} searchWord
+ * @return {string[][]}
+ */
+var suggestedProducts1 = (products, searchWord) => new Trie()
+    .buildTrie(products)
+    .searchWord(searchWord);
+
+class Node {
+    constructor () {
+        this.children = new Map();
+        this.isWord = false;
+    }
+};
+
+class Trie {
+    constructor () {
+        this.root = new Node();
+    }
+
+    buildTrie (products) {
+        for (const word of products) {
+            this.insert(word);
+        }
+
+        return this;
+    }
+    
+    insert (word, { root: node } = this) {        
+        for (const char of word.split('')) {
+            const child = (node.children.get(char) ?? new Node());
+            
+            node.children.set(char, child);
+
+            node = child;
+        }
+
+        node.isWord = true;
+    }
+    
+    searchWord (searchWord, buffer = [], suggestions = []) {
+        for (const char of searchWord.split('')) {
+            const prefix = this.getPrefix(buffer, char);
+            const words = this.getSuggestions(prefix);
+
+            suggestions.push(words);
+        }
+        
+        return suggestions;
+    }
+
+    getPrefix (buffer, char) {
+        buffer.push(char);
+
+        return buffer.join('');
+    }
+    
+    getSuggestions (prefix, words = []) {
+        const node = this.getPrefixNode(prefix);
+
+        const isInvalidPrefix = (node === null);
+        if (isInvalidPrefix) return words
+        
+        return this.search(node, prefix, words);
+    }
+
+    getPrefixNode (prefix, { root: node } = this) {
+        for (const char of prefix.split('')) {
+            const child = (node.children.get(char) ?? null);
+
+            const isLeafNode = (child === null);
+            if (isLeafNode) return null;
+
+            node = child;
+        }
+
+        return node;
+    }
+
+    search (node, word, words) {
+        const isBaseCase = (words.length === 3);
+        if (isBaseCase) return words;
+
+        if (node.isWord) words.push(word);
+
+        return this.dfs(node, word, words);
+    }
+
+    dfs (node, word, words) {
+        for (const char of this.getChars()) {
+            const child = (node.children.get(char) ?? null);
+
+            const isLeafNode = (child === null);
+            if (isLeafNode) continue;
+        
+            this.search(child, (word + char), words);
+        }
+
+        return words;
+    }
+
+    getChars () {
+        return new Array(26).fill()
+            .map((_, index) => String.fromCharCode((index + 97)));
+    }
+};