# 归档 2015年4月

## 题目描述：

Given two strings s and t, determine if they are isomorphic.

Two strings are isomorphic if the characters in s can be replaced to get t.

All occurrences of a character must be replaced with another character while preserving ...

## 题目描述：

Count the number of prime numbers less than a non-negative number, n

Hint: The number n could be in the order of 100,000 to 5,000,000.

References:

How Many Primes Are There? (https://primes.utm.edu/howmany ...

## 题目描述：

Remove all elements from a linked list of integers that have value val.

Example
Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6
Return: 1 --> 2 --> 3 --> 4 --> ...

## 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 ...

## SAE新浪微博Python SDK CERTIFICATE_VERIFY_FAILED解决方法 作者是 在线疯狂 发布于 2015年4月22日 在 django, SAE.

```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 ...```