摘要：
Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element 阅读全文
摘要：
Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Example 2: Note: You may assume the tree (i.e., the given root no 阅读全文
摘要：
Given an array of integers, 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements that appear twi 阅读全文