北叶青藤

摘要： Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and r 阅读全文

摘要： Given a list of unique words. Find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e.words[i] + 阅读全文

摘要： All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: "ACGAATTCCG". When studying DNA, it is sometimes useful to 阅读全文

摘要： Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), retur 阅读全文

摘要： Count the number of prime numbers less than a non-negative number, n 阅读全文

摘要： Flip Game I Problem Description: You are playing the following Flip Game with your friend: Given a string that contains only these two characters: + a 阅读全文

摘要： Word Pattern | Given a pattern and a string str, find if str follows the same pattern. Examples: Notes: solution: Split the string, and add the pair t 阅读全文

摘要： Given a string, we can "shift" each of its letter to its successive letter, for example: "abc" -> "bcd". We can keep "shifting" which forms the sequen 阅读全文

摘要： Given a list of words and two words word1 and word2, return the shortest distance between these two words in the list. For example, Assume that words 阅读全文

摘要： Design an algorithm to encode a list of strings to a string. The encoded string is then sent over the network and is decoded back to the original list 阅读全文