摘要： A peak element is an element that is greater than its neighbors. Given an input array where num[i] ≠ num[i+1], find a peak element and return its inde 阅读全文

摘要： Given an array of sizen, find the majority element. The majority element is the element that appears more than⌊ n/2 ⌋times.You may assume that the arr... 阅读全文

摘要： Given a positive integer, return its corresponding column title as appear in an Excel sheet.For example: 1 -> A 2 -> B 3 -> C ... 26 ->... 阅读全文