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How can I multiply and divide using only bit shifting and adding?
... to decompose one of the numbers by powers of two, like so:
21 * 5 = 10101_2 * 101_2 (Initial step)
= 10101_2 * (1 * 2^2 + 0 * 2^1 + 1 * 2^0)
= 10101_2 * 2^2 + 10101_2 * 2^0
= 10101_2 << 2 + 10101_2 << 0 (Decomposed)
= 10101_2 * 4 + 10101_2 *...
How to use the TextWatcher class in Android?
...gered again, starting an infinite loop. You should then add like a boolean _ignore property which prevent the infinite loop.
Exemple:
new TextWatcher() {
boolean _ignore = false; // indicates if the change was made by the TextWatcher itself.
@Override
public void afterTextC...
How to get the last N rows of a pandas DataFrame?
... dataframe df1 and df2 (df1 is vanila dataframe, df2 is indexed by 'STK_ID' & 'RPT_Date') :
3 Answers
...
What is in your Mathematica tool bag? [closed]
...and Sow which mimics/extends the behavior of GatherBy:
SelectEquivalents[x_List,f_:Identity, g_:Identity, h_:(#2&)]:=
Reap[Sow[g[#],{f[#]}]&/@x, _, h][[2]];
This allows me to group lists by any criteria and transform them in the process. The way it works is that a criteria function (f...
Migration: Cannot add foreign key constraint
... $table->increments('id', true);
$table->integer('user_id')->unsigned();
$table->string('priority_name');
$table->smallInteger('rank');
$table->text('class');
$table->timestamps('timecreated');
});
Schema::table('priorities'...
What Automatic Resource Management alternatives exist for Scala?
...Reader(new FileReader("file.txt"))) { reader =>
Iterator.unfold(())(_ => Option(reader.readLine()).map(_ -> ())).toList
}
or using Using.resource avoid Try
val lines: Seq[String] =
Using.resource(new BufferedReader(new FileReader("file.txt"))) { reader =>
Iterator.unfold((...
数据结构与本地数据库 07：错题记录、事务与统计图 · App Inventor 2 中文网
... 实例名
组件
本课配置
标签_标题
标签
Width=Fill parent；FontSize=24；TextColor=#183153；Text=知识卡片 · 第 7课
微数据库1
微数据库
Namespace=CardsB07
按钮_记错
按...
Rename multiple files in a directory in Python [duplicate]
...e os.rename(src, dst) to rename or move a file or a directory.
$ ls
cheese_cheese_type.bar cheese_cheese_type.foo
$ python
>>> import os
>>> for filename in os.listdir("."):
... if filename.startswith("cheese_"):
... os.rename(filename, filename[7:])
...
>>>
$ ls
c...
How to save a PNG image server-side, from a base64 data string
...plode(';', $data);
list(, $data) = explode(',', $data);
$data = base64_decode($data);
file_put_contents('/tmp/image.png', $data);
And as a one-liner:
$data = base64_decode(preg_replace('#^data:image/\w+;base64,#i', '', $data));
An efficient method for extracting, decoding, and checking for e...
How to read keyboard-input?
...
try
raw_input('Enter your input:') # If you use Python 2
input('Enter your input:') # If you use Python 3
and if you want to have a numeric value
just convert it:
try:
mode=int(raw_input('Input:'))
except ValueError:
...