Code Hunter

Monday, March 6, 2017

Git tricks.

1. Copy commits from one branch to other:

Copied from http://weblog.avp-ptr.de/20120928/git-how-to-copy-a-range-of-commits-from-one-branch-to-another/

2. Join several commits in one:

Use git rebase -i <after-this-commit> and replace "pick" on the second and subsequent commits with "squash" or "fixup", as described in the manual.

In this example, <after-this-commit> is either the SHA1 hash or the relative location from the HEAD of the current branch from which commits are analyzed for the rebase command. For example, if the user wishes to view 5 commits from the current HEAD in the past the command is git rebase -i HEAD~5.

From: http://stackoverflow.com/questions/5189560/squash-my-last-x-commits-together-using-git

Thursday, March 2, 2017

Good json online checker tool

http://codebeautify.org/jsonviewer

Monday, February 27, 2017

Cool capybara sheet.

https://gist.github.com/zhengjia/428105

=Navigating=
    visit('/projects')
    visit(post_comments_path(post))

=Clicking links and buttons=
    click_link('id-of-link')
    click_link('Link Text')
    click_button('Save')
    click('Link Text') # Click either a link or a button
    click('Button Value')

=Interacting with forms=
    fill_in('First Name', :with => 'John')
    fill_in('Password', :with => 'Seekrit')
    fill_in('Description', :with => 'Really Long Text…')
    choose('A Radio Button')
    check('A Checkbox')
    uncheck('A Checkbox')
    attach_file('Image', '/path/to/image.jpg')
    select('Option', :from => 'Select Box')

=scoping=
    within("//li[@id='employee']") do
      fill_in 'Name', :with => 'Jimmy'
    end
    within(:css, "li#employee") do
      fill_in 'Name', :with => 'Jimmy'
    end
    within_fieldset('Employee') do
      fill_in 'Name', :with => 'Jimmy'
    end
    within_table('Employee') do
      fill_in 'Name', :with => 'Jimmy'
    end

=Querying=
    page.has_xpath?('//table/tr')
    page.has_css?('table tr.foo')
    page.has_content?('foo')
    page.should have_xpath('//table/tr')
    page.should have_css('table tr.foo')
    page.should have_content('foo')
    page.should have_no_content('foo')
    find_field('First Name').value
    find_link('Hello').visible?
    find_button('Send').click
    find('//table/tr').click
    locate("//*[@id='overlay'").find("//h1").click
    all('a').each { |a| a[:href] }

=Scripting=
    result = page.evaluate_script('4 + 4');

=Debugging=
    save_and_open_page

=Asynchronous JavaScript=
    click_link('foo')
    click_link('bar')
    page.should have_content('baz')
    page.should_not have_xpath('//a')
    page.should have_no_xpath('//a')

=XPath and CSS=
    within(:css, 'ul li') { ... }
    find(:css, 'ul li').text
    locate(:css, 'input#name').value
    Capybara.default_selector = :css
    within('ul li') { ... }
    find('ul li').text
    locate('input#name').value

Thursday, February 23, 2017

Reverse transparent image.

Let we have the png file:

And the task is use this as mask with white background to see other background bellow.
At first we need to revert transparency. I use imagemagick CLI for this:

> convert london-landmark.png -background white -alpha background -channel a -negate +channel london-landmark2.png

The result is:

Then it looks on the page:

Wednesday, February 22, 2017

Full decs task

In a casino, all the playing cards got mixed up, and some of them got lost.
You have to collect as many full decks as possible.

You get N mixed up French playing cards as your input.

The cards are of the following ranks:
2, 3, 4, 5, 6, 7, 8, 9, T, J, Q, K, A

The four suits are:
S (Spade), C (Club), H (Heart), D (Diamond)

The cards are given using their rank followed by their suit:

2 of Spades: 2S
Ace of Clubs: AC
10 of Hearts: TH

Write a function that will accept an array of cards and return the number of full decks contained in the array.

Examples:
a) ["9C", "KS", "AC", "AH", "8D", "4C", "KD", "JC", "7D", "9D", "2H", "7C", "3C", "7S", "5C", "6H", "TH"] -> 0

b) ["2S", "2C", "2D", "2H", "3S", "3C", "3D", "3H", "4S", "4C", "4D", "4H", "5S", "5C", "5D", "5H", "6S", "6C", "6D", "6H", "7S", "7C", "7D", "7H", "8S", "8C", "8D", "8H", "9S", "9C", "9D", "9H", "TS", "TC", "TD", "TH", "JS", "JC", "JD", "JH", "QS", "QC", "QD", "QH", "KS", "KC", "KD", "KH", "AS", "AC", "AD", "AH", "2S", "2C", "2D", "2H", "3S", "3C", "3D", "3H", "4S", "4C", "4D", "4H", "5S", "5C", "5D", "5H", "6S", "6C", "6D", "6H", "7S", "7C", "7D", "7H", "8S", "8C", "8D", "8H", "9S", "9C", "9D", "9H", "TS", "TC", "TD", "TH", "JS", "JC", "JD", "JH", "QS", "QC", "QD", "QH", "KS", "KC", "KD", "KH", "AS", "AC", "AD", "AH", "2S", "2C", "2D", "2H", "3S", "3C", "3D", "3H", "4S", "4C", "4D", "4H", "5S", "5C", "5D", "5H", "6S", "6C", "6D", "6H", "7S", "7C", "7D", "7H", "8S", "8C", "8D", "8H", "9S", "9C", "9D", "9H", "TS", "TC", "TD", "TH", "JS", "JC", "JD", "JH", "QS", "QC", "QD", "QH", "KS", "KC", "KD", "KH", "AS", "AC", "AD"] -> 2

def full_decks_count input
res = input.inject({}) do |h, el|
h[el] ||= 0
h[el] += 1
h
end

return 0 if res.count < 52
res.values.min
end