Velut arbor aevo.
Given a non-empty array of numbers, a0, a1, a2, … , an-1, where 0 ≤ ai < 231. Find the maximum result of ai XOR aj, where 0 ≤ i, j < n. Could you do this in O(n) runtime?Continue reading “[Leetcode]421. Maximum XOR of Two Numbers in an Array”
Given a 2D board and a list of words from the dictionary, find all words in the board. Each word must be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically neighboring. The same letter cell may not be used more than once in a word. Example: Input: board = [ ['o','a','a','n'], ['e','t','a','e'], ['i','h','k','r'], ['i','f','l','v'] ] words =Continue reading “[Leetcode]212. Word Search II”["oath","pea","eat","rain"]Output:["eat","oath"]
A trie, or a prefix tree, refers to an ordered data structure that is usually used to store strings (Wikipedia). The picture on the above is an example where a trie stores [ape,apple,are,art]. Now let’s take a closer look at it and it’s not hard to find that: