摘要： 问题描述： Given a non-empty array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear 阅读全文

摘要： 问题描述： Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may 阅读全文

摘要： 问题描述： Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root) 阅读全文

摘要： 问题描述： Given two binary trees, write a function to check if they are the same or not. Two binary trees are considered the same if they are structurally 阅读全文

摘要： 问题描述： Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is 阅读全文

摘要： 问题： You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can yo 阅读全文

摘要： 问题描述： Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. Example 阅读全文

摘要： 问题描述： Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid 阅读全文

摘要： import java.io.*//生成代表输入流的对象fis=new FileInputStream("e:/src/from.txt") //生成代表输出流的对象 fos=new FileOutputStream("e:/src/to.txt")//生成一个字节数组byte [] buffer = new byte[1024]//当读取的文件为空值时，read方法返回值为-1int temp... 阅读全文

摘要： score(self, X, y, sample_weight=None) 作用：返回该次预测的系数R2 其中R2 =（1-u/v）。u=((y_true - y_pred) ** 2).sum() v=((y_true - y_true.mean()) ** 2).sum() 其中可能得到的最好的 阅读全文