摘要：
Given an array of integers sorted in ascending order, find the starting and ending position of a given target value. Your algorithm's runtime complexi 阅读全文
摘要：
Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand. (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2). You a 阅读全文
摘要：
Given n pairs of parentheses, write a function to generate all combinations of well formed parentheses. For example, given n = 3, a solution set is: [ 阅读全文
摘要：
Given a string containing just the characters '(' and ')', find the length of the longest valid (well formed) parentheses substring. For "(()", the lo 阅读全文