Some interview questions

You have 2 files:
a.txt
aaa bbb ccc fddf
ddd eee fff

b.txt
111 222 333
444 555 666

Mix their output like this:
aaa 111 bbb 222 ccc 333
ddd 444 eee 555 fff 666

My ruby solution:

atext=File.readlines('a.txt').map {|line| line.split}

btext=File.readlines('b.txt').map {|line| line.split}

out=[]

(btext.size > atext.size ? btext.size : atext.size).times do |i|

    if btext[i].nil?

        out<<atext[i]

    elsif atext[i].nil?

        out<<btext[i]

    else

        out<<atext[i].zip(btext[i]).flatten.compact

    end

end

File.open("out.txt", "w+") do |f|

  out.each { |element| f.puts(element.join(' '))}

end

MS VS 2010 - TFS 2008 integration pains

From the never ending pains of using MS Team Foundation Server, came another one - an annoying  issue with comment policy:

---------------------------
Microsoft Visual Studio
---------------------------
Internal error in Changeset Comments Policy. Error loading the Changeset Comments Policy policy (The policy assembly 'Microsoft.TeamFoundation.PowerTools.CheckinPolicies.ChangesetComments, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not registered.). Installation instructions: To install this policy, follow the instructions in CheckForComments.cs.

Error loading the Changeset Comments Policy policy (The policy assembly 'Microsoft.TeamFoundation.PowerTools.CheckinPolicies.ChangesetComments, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' is not registered.). Installation instructions: To install this policy, follow the instructions in CheckForComments.cs.
---------------------------
OK   
---------------------------


Bellow is the solution (cooked from VS 2008 similar issue and some other answers around ms forum).


A. Modify Registry so VS2010 Can Find The Policies

Edit the paths (using your Team Foundation PowerTools installation path) below and save text in a .reg file (or use regedit)

-----------------------------------------------------------------------------------
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\10.0\TeamFoundation\SourceControl\Checkin Policies]
"Microsoft.TeamFoundation.PowerTools.CheckinPolicies.ChangesetComments"="c:\\Program Files\\Microsoft Team Foundation Server 2008 Power Tools\\Check-in Policy Pack\\Microsoft.TeamFoundation.PowerTools.CheckinPolicies.ChangesetComments.dll"
"Microsoft.TeamFoundation.PowerTools.CheckinPolicies.ForbiddenPatternsPolicy"="c:\\Program Files\\Microsoft Team Foundation Server 2008 Power Tools\\Check-in Policy Pack\\Microsoft.TeamFoundation.PowerTools.CheckinPolicies.ForbiddenPatternsPolicy.dll"
"Microsoft.TeamFoundation.PowerTools.CheckinPolicies.WorkItemQueryPolicy"="c:\\Program Files\\Microsoft Team Foundation Server 2008 Power Tools\\Check-in Policy Pack\\Microsoft.TeamFoundation.PowerTools.CheckinPolicies.WorkItemQueryPolicy.dll"
"Microsoft.TeamFoundation.PowerTools.CheckinPolicies.CustomPathPolicy"="c:\\Program Files\\Microsoft Team Foundation Server 2008 Power Tools\\Check-in Policy Pack\\Microsoft.TeamFoundation.PowerTools.CheckinPolicies.CustomPathPolicy.dll"
-----------------------------------------------------------------------------------


B. Set Binding Redirects in DevEnv.Exe.Config
1.     Close all instances of devenv.exe
2.     Find where VS2010 Team Explorer or VS2010 devenv.exe is installed. Typically
C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE
3.     Backup the existing devenv.exe.config file
4.     Edit devenv.exe.config by adding the following in the <runtime><assemblyBinding> section:
<dependentAssembly>
<assemblyIdentity name="Microsoft.TeamFoundation.WorkItemTracking.Client" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
<bindingRedirect oldVersion="9.0.0.0" newVersion="10.0.0.0"/>
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.TeamFoundation.Client" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
<bindingRedirect oldVersion="9.0.0.0" newVersion="10.0.0.0"/>
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.TeamFoundation.Common" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
<bindingRedirect oldVersion="9.0.0.0" newVersion="10.0.0.0"/>
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.TeamFoundation.VersionControl.Client" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
<bindingRedirect oldVersion="9.0.0.0" newVersion="10.0.0.0"/>
</dependentAssembly>
<dependentAssembly>
<assemblyIdentity name="Microsoft.TeamFoundation.VersionControl.Common" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
<bindingRedirect oldVersion="9.0.0.0" newVersion="10.0.0.0"/>
</dependentAssembly>
5.     Save devenv.exe.config

C. Enjoy

Multi-dimensional array in python

I get an interesting problem yesterday (from http://groups.yahoo.com/group/mensa_romania/message/8139):
Calculate the sum of the elements in a slice from a multi-dimensional array (six dimensions and at least 25 elements per dimension).

First unrefined solution:


#!/usr/bin/python

#http://groups.yahoo.com/group/mensa_romania/message/8139
#Se da o matrice patrata M de dimensiune (NxN)
#Se cere ca pentru toate perechile de indici sa se calculeze suma tuturor
#elementelor anterioare.
#De exemplu:
#Pentru elementul (3,4) sa se calculeze suma:
#M[1,1]+M[1,2] +M[1,3]+M[ 1,4]+M[2,1]+M[2,2] +M[2,3]+M[ 2,4]+M[3,1]+M[3,2] +M[3,3]+M[ 3,4]

import sys
from math import sqrt
import time
import random

max_array = 25
aitime=time.time()
a=[[[[[(1000*random.random()) for dim1 in range(max_array)] for dim2 in range(max_array)] for dim3 in range(max_array)] for dim4 in range(max_array)] for dim5 in range(max_array)]
aftime=time.time()

#print a[10][3][22][21][5]

section=[2,23,13,22,19]
sum=0
sitime=time.time()
for i1 in range(section[0]):
for i2 in range(section[1]):
for i3 in range(section[2]):
for i4 in range(section[3]):
for i5 in range(section[4]):
sum+=a[i1][i2][i3][i4][i5]
sftime=time.time()

print "Sum of numbers = ", sum
print "Generate array in ", sftime-sitime
print "Calculate sum in ", aftime-aitime


Automaticaly remove old clearcase dinamic views

If you ever had control over a clearcase view server in a medium/big development team, you did encounter this issue for sure: many dinamic views left unused on the view server tacking up space (either team member moved away and left their views behind, new projects apeared and team member forgot about their old views, and so on).

Faced with these issue, I cooked up a short perl script that periodicaly (run by cron weekly) check for views older than 6 months (180 days) and notify the users about their old views being removed next time (one week in future).
Also it forces undo checkouts to avoid troubles.

Bellow is the script:


#!/usr/bin/env perl -w
#===============================================================================
#
# FILE: rm_old_views.pl
#
# USAGE: ./rm_old_views.pl
#
# DESCRIPTION: Remove clearcase views not touched in last 6 months
#
# AUTHOR: MariusCC
# VERSION: 1.0
# CREATED: 08/22/2008 03:08:43 PM Russian Standard Time
# REVISION: 1.0
#===============================================================================

use strict;
use warnings;
use Carp;
use Getopt::Long;
use File::Temp qw/tempfile tempdir/;
use File::Copy;
use Sys::Hostname;

my ($debug, $hostname, $mailhost, $help, $workdir, $lastused, @cmd);

GetOptions(
'debug+' => \$debug,
'hostname:s' => \$hostname,
'mailhost:s' => \$mailhost,
'workdir:s' => \$workdir,
'lastused:s' => \$lastused,
'help' => \$help
);
&usage() if $help;

#set default options
$debug ||= 0;
$mailhost ||= "smtp.yourdomain.com";
$workdir ||= "/var/spool/rmviews";
$hostname ||= hostname();
mkdir $workdir if (!-d $workdir); #create workdir if it doesn't exist
$lastused ||= 180 * 86400;
$lastused = time() - $lastused; #go back a number of days in the past

#define utilities
my $ct = '/usr/atria/bin/cleartool';
my $allviewslst = "$workdir/allviews.lst";
my $oldviewslst = "$workdir/oldviews.lst";
my $lock = "$workdir/lock";

#
#subroutines used in script
#

#execute a system call
sub _system (@) {
my @args = @_;

system(@args) and warn "Could not fork @args\n";
}

#open a file and return the handle
sub _open ($) {
my ($file) = @_;

open(my $fh, $file) or croak "Could not open $file: $!\n";
return ($fh);
}

#remove an old view
sub rmview($) {
my $view = $_;

if (checkoldview($view)) {

#for each view list checkouts, if they exist force unco, then remove view
$view =~ /\/(\w+)\.vws/g; #get view tag
my $viewtag = $1;
my $lsco = "$workdir/lsco";
my @args = qq/$ct setview -exec "$ct lsco -cview -avobs -short |sort > $lsco" $viewtag/;
if ($debug){
print "executing @args\n";
}else{
_system(@args);
}
if (-f $lsco) {
my $fh = _open($lsco);
while (<$fh>) {
@args = qq/$ct setview -exec "$ct unco -rm $_" $viewtag/;
if ($debug){
print "executing @args\n";
}else{
_system(@args);
}
}
close $fh if defined $fh;
undef $fh;
unlink $lsco;
}
@args = qq/$ct rmview -force $view/;
if ($debug){
print "executing @args\n";
}else{
_system(@args);
}
}
}

#check if a view is older then $lastused, return 0/1
sub checkoldview($;$) {
my $view = $_;
my $forcemail = $_;
undef $forcemail if $debug;

my $oldview = 0;
if ($view =~ /\/*.\.vws/i) { #skip garbage from list
$view =~ s/\n//;
if (-d $view) {
print "analize $view/.access_info\n" if $debug;

#my ($dev, $ino, $mode, $nlink, $uid, $gid, $rdev, $size, $atime, $mtime, $ctime, $blksize, $blocks) =
my @stats = stat "$view/.access_info" if (-f "$view/.access_info");
print "uid=$stats[4]\nmtime=$stats[9]\n" if $debug;
if ($stats[9] < $lastused) {
print "view $view is old\n" if $debug;
my $uid = $stats[4];
$oldview++;
mailuser($view, $uid) if $forcemail;
}
}
}
return $oldview;
}

#mail a user regarding an old view
sub mailuser($$) {
my $view = shift;
my $uid = shift;

$view =~ /\/(\w+)\.vws/g; #get view tag
$view = $1;
print "view tag to be removed: $view\n" if $debug;
print "get name for $uid\n" if $debug;
my $name = getpwuid($uid);
my $name ||= 'root';
my $mailtxt = "$workdir/mailtxt_$name";
$name .= '@yourdomain.com';
print "mail to $name\n" if $debug;
my $fh = _open "> $mailtxt";
my $rmtime = localtime(time() + 604800); #add 7 days from now
print "remove time is $rmtime\n" if $debug;
print $fh <Please read this message in its entirety to avoid losing valuable
project data. In accordance with the Company Management Policy, the
view $view is scheduled to be removed on $rmtime.
If you do not remove or write to the view $view,
it will be removed on $rmtime.
************************************************************************
View info
EOF
close $fh if defined $fh;
undef $fh;
my @args = qq/$ct lsview -long $view >> $mailtxt/;
_system(@args);
@args = qq/cat $mailtxt | \/usr\/bin\/mailx -s "View removal notice: $view" $name/;
print "exec @args\n" if $debug;
_system(@args);
unlink $mailtxt;
}

sub usage() {
print "\n\nUsage : rm_old_views [--option] Remove views not used in the last 6 months using options\n";
print " --debug Run in debug mode\n";
print " --hostname Remove only views hosted on hostname\n";
print " --help This one ;)\n";
exit(1);
}

#
#END of subs definitions
#

#define some more vars
my ($fhr, $fhw, @stats);

die "Another instance of $0 is running!\n" if (-f $lock);
@cmd = qq/date > $lock/;
_system(@cmd);

#remove oldviews from $oldviewslst
if (-f $oldviewslst) {
$fhr = _open($oldviewslst);
while (<$fhr>) {
rmview($_);
}
close $fhr if defined $fhr;
}

#find all views on host
@cmd = qq/$ct lsview \| \/usr\/bin\/grep -i $hostname \| \/usr\/bin\/awk \'{print \$2}\' > $allviewslst/;
_system(@cmd);

#find out how old are they, and add older ones to $oldviewslst
$fhr = _open($allviewslst);
$fhw = _open "> $oldviewslst";
while (<$fhr>) {
my $vws = $_;
$vws =~s/\n//g;
print $fhw "$vws\n" if (checkoldview($vws,1));
}
close $fhr if defined $fhr;
close $fhw if defined $fhw;

@cmd = qq/rm -fr $lock/;
_system(@cmd);