My_Jobs的专栏

题目：Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum.For example:Given the below binary tree

问题：有一个100层高的楼，如果一个鸡蛋从n层掉下来或者n层以上，鸡蛋就会碎掉。已知，现在有两个鸡蛋，找到满足条件的n，使在最坏情况下，丢鸡蛋的次数最少。原题链接可以转到wiki：点击打开链接很明显，不管egg1怎么丢，egg2肯定得线性得丢。我们假设egg1每次丢10层，即按10f, 20f, 30f, 40f, 50f, 60f, 70f, 80f, 90f, 100f。则，如

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:"((()))", "(()())", "(())()", "()(())", "()()