pku_Coder的博客

提供两种解法,比较类似 一种是从后向前维护单调递增栈; 另一种是从前向后维护单调递减栈.描述农夫John 的N(1 ≤ N ≤ 80,000)只奶牛中，有一些也许正在经历发型糟糕的一天。每只奶牛对自己乱糟糟的发型都有自知之明，农夫John想知道所有奶牛能看到其他奶牛头顶的数量之和。任意奶牛i身高记为 hi (1 ≤ hi ≤ 1,000,000,000)，所有奶牛面向东方（本题示意图的右面）依

Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23"

Given a string containing just the characters ‘(‘, ‘)’, ‘{‘, ‘}’, ‘[’ and ‘]’, determine if the input string is valid.The brackets must close in the correct order, “()” and “()[]{}” are all valid but “

Given a collection of intervals, merge all overlapping intervals.For example,Given [1,3],[2,6],[8,10],[15,18],return [1,6],[8,10],[15,18].思路：按照start排序，然后遍历全部元素，如果完全错开就放进去，如果没有完全错开就修改上一区间的end值。用vector

Given an absolute path for a file (Unix-style), simplify it.For example,path = "/home/", => "/home"path = "/a/./b/../../c/", => "/c"Corner Cases:Did you consider the case where path = "/../"?In thi