作者归档：在线疯狂

题目描述：

Write an algorithm to determine if a number is "happy".

A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and ...

一个搭建在SAE上的Django应用，使用新浪微博提供的Python SDK已经稳定运行一年有余，但最近开始持续出现微博认证失败的状况。

摘录微博Python SDK的错误提示如下所示：

ERROR:django.request:Internal Server Error: /weibo/auth/
Traceback (most recent call last):
  File "/usr/local/sae/python/3rd/django-1.5/django/core/handlers/base.py", line 115, in get_response
    response = callback(request ...

在Django ORM中，使用order_by()方法对包含关联关系的模型进行排序时，返回结果中可能会出现重复元素。

假设有下面的两个模型Client和Interaction，Client为顾客，Interaction为交互。

Client类中包含顾客的姓名和联系方式，Interaction类中包含标题、时间、待办事项、截止日期。

class Client(models.Model):
    name = models.CharField(max_length=255, unique=True)
    contact = models.CharField(max_length=255, null=True, blank=True)

class Interaction(models.Model):
    client = models.ForeignKey ...

题目描述：

Given a range [m, n] where 0 <= m <= n <= 2147483647, return the bitwise AND of all numbers in this range, inclusive.

For example, given the range [5, 7], you should return 4.

题目大意：

给定范围[m, n ...

题目描述：

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of ...