摘要：
Ransom Note Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true 阅读全文
摘要：
Given a paragraph and a list of banned words, return the most frequent word that is not in the list of banned words. It is guaranteed there is at leas 阅读全文
摘要：
Count Binary Substrings Give a string s, count the number of non-empty (contiguous) substrings that have the same number of 0's and 1's, and all the 0 阅读全文