ruby - How to refactor this code to remove output variable? - 


def peel array   output = []    while ! array.empty?     output << array.shift     mutate! array   end    output.flatten end

i have not included mutate! method, because interested in removing output variable. mutate! call important because cannot iterate on array using each because array changing.

edit: getting array output, want. method works correctly, think there way collect array.shift values without using temp variable.

edit #2: ok, here mutate! method , test case:

def mutate! array   array.reverse! end  = (1..5).to_a peel( ).should == [ 1, 5, 2, 4, 3 ]

it doesn't matter if peel modifies array. guess should called peel!. yes, mutate! must called after each element removed.

all reversing makes me dizzy.

def peel(array)   indices = array.size.times.map |i|     = -i if i.odd?     = i/2   end    array.values_at(*indices) # indices [0, -1, 1, -2, 2] in example end  = (1..5).to_a p peel(a) #=>[1, 5, 2, 4, 3]

Comments

Post a Comment

Popular posts from this blog

java.util.scanner - How to read and add only numbers to array from a text file -

i'm learning java , have question regarding reading file want read numbers file contains strings well. here example of file: 66.56 "3 java 3-43 5-42 2.1 1 and here coding: public class test { public static void main (string [] args){ if (0 < args.length) { file x = new file(args[0]); try{ scanner in = new scanner( new fileinputstream(x)); arraylist<double> test = new arraylist<>(); while(in.hasnext()){ if(in.hasnextdouble()){ double f=in.nextdouble(); test.add(f);} else {in.next();} } catch(ioexception e) { system.err.println("exception during reading: " + e); } } my problem add 66.56,2.1 , 1 doesn't add 3 after "3 or ignores 3-43 , 5-42 can tell me how skip strings , add doubles here? thanks all said 3 ie; "3, 3-43 , 4-42 strings either u read string , split , check number @ " , - or put in space between characters , integers. jvm after compilation tre
Read more

html - Repeat image to extend header to fill screen -

i have header (2300x328px) , image (456x328px). want second image extend header left , right, header fills whole width availiable.it needs connect without overlapping, because there pattern. here image of mean: http://imgur.com/0ji3hae circles pattern (why should not overlap) , images extend header can repeated infinitely. for pattern align need align background pattern according header image (ex. center, left etc) , make sure pattern starts @ right place. i made fiddle explain mean - http://jsfiddle.net/taneleero/g99xa/ .header { background:url(http://i.imgur.com/bzvtzl4.jpg) repeat-x center; } .header img { display:block; margin:0px auto; }
Read more

javascript - Backbone.js getting target attribute -

i trying figure out why value of e.target.getattribute('data-text') becoming null when go html backbone js file. html: <script type="text/template" id="lesson-template"> <span id="lesson-title"><%= tracks[0].title %></span> <select class="sel"> <% _.each(tracks, function(track) { %> <option value = "<%= track.text %>" data-text="<%= track.title %>"><%= track.title %></option> <% }); %> </select> <p id="tracktext"><%= tracks[0].text %></p> </script> js: window.librarylessonview = lessonview.extend({ events: { "change .sel " : "changetext" }, changetext: function(e) { alert(e.target.getattribute('data-text')); //i getting null value here! document.getelementbyid("lesson-title").innerhtml= e.target.getattribute('data-text&
Read more