Ellenfeifei的博客

题目： Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array.  Example： Input: 3 / \ 9 20 / \ 15 7 Output: [3, 14.5, 11] Ex

题目： Given an integer n, find the closest integer (not including itself), which is a palindrome. The 'closest' is defined as absolute difference minimized between two integers. example： Input

1.动态规划 将问题分解成子问题，自底向上的求解子问题的最优解，进而求出原问题的一个最优解（有可能有多个最优解，只求出其中的一个即可）。 2.题目 You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewe