作者归档：在线疯狂

下面的JavaScript代码利用HTML5 canvas实现了动态的雪花飘落效果，CPU开销也比较小。

原文链接：http://www.oschina.net/code/snippet_436266_46013

JavaScript代码：

<canvas id="christmasCanvas" style="top: 0px; left: 0px; z-index: 5000; position: fixed; pointer-events: none;" ></canvas>

<script type="text/javascript">
  var snow = function() {
    if(1==1) {
      var ...

题目描述：

Given two arrays of length m and n with digits 0-9 representing two numbers. Create the maximum number of length k <= m + n from digits of the two. The relative order of the digits from the same array ...

题目描述：

There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle every third bulb (turning on if it's off or turning off ...

在存储或者传输图像时，我们经常需要将图像转换成字符串。

与其他编程语言一样（比如Java），Python也可以实现将图像用字符串进行表示。

使用Python进行转换非常的简单，关键部分就是使用“base64”模块，它提供了标准的数据编码解码方法。

图像转换成字符串

Python代码：

import base64
 
with open("t.png", "rb") as imageFile:
    str = base64.b64encode(imageFile.read())
    print str

输出：

iVBORw0KGgoAAAANSUhEUgAAAuAAAACFCAIAAACVGtqeAAAAA3
NCSVQICAjb4U/gAAAAGXRFWHRTb2Z0d2FyZQBnbm9tZS1zY3Jl
ZW5zaG907wO/PgAAIABJREFUeJzsnXc81d8fx9+fe695rYwIaa
...

字符串转换成图像

Python代码：

fh = open("imageToSave.png", "wb ...

题目描述：

Given a string array words, find the maximum value of length(word[i]) * length(word[j]) where the two words do not share common letters. You may assume that each word will contain only lower case letters. If no ...