摘要： 题目如下： We are given an array A of N lowercase letter strings, all of the same length. Now, we may choose any set of deletion indices, and for each stri 阅读全文

摘要： 题目如下： Given a string S that only contains "I" (increase) or "D" (decrease), let N = S.length. Return any permutation A of [0, 1, ..., N] such that for 阅读全文

摘要： 题目如下： Given an array A of integers, return true if and only if it is a valid mountain array. Recall that A is a mountain array if and only if: A.lengt 阅读全文