摘要：
Given a list of sorted characters letterscontaining only lowercase letters, and given a target letter target, find the smallest element in the list th 阅读全文
摘要：
Given a sorted (in ascending order) integer array nums of n elements and a target value, write a function to search target in nums. If targetexists, t 阅读全文
摘要：
You have a total of n coins that you want to form in a staircase shape, where every k-th row must have exactly k coins. Given n, find the total number 阅读全文