Wednesday, May 09, 2018

Trying out my Python 3 skills on HackerRank

I've been using HackerRank to get my Python coding chops up a little better then where they've been before.

Tried a medium challenge on HackerRank called Piling Up

My solution isn't as elegant as others but it works and constantly reduces the size of the cube size list that need to be rearranged from horizontal to vertical where the block size needs to be equal or smaller than the block below it.


for tests in range(int(input())):
    cube_length = int(input())
    list_of_cubes = list(map(int, input().split()))

    last_value_placed_on_stack = 0
    all_items_on_placed_on_stack = False
    cannot_stack_anymore = False

    a = 0
    z = int(len(list_of_cubes)) - 1

    while a < int(len(list_of_cubes)):
        if cannot_stack_anymore:
            break
        if int(len(list_of_cubes)) == 1:
            if int(list_of_cubes[a]) <= last_value_placed_on_stack:
                all_items_on_placed_on_stack = True
                break
            else:
                break
        while z > 0:
            if list_of_cubes[a] >= int(list_of_cubes[z]):
                if list_of_cubes[a] <= last_value_placed_on_stack or last_value_placed_on_stack == 0:
                    last_value_placed_on_stack = list_of_cubes[a]
                    list_of_cubes.pop(a)
                    z = z - 1
                    break
                else:
                    cannot_stack_anymore = True
                    break
            if list_of_cubes[z] >= int(list_of_cubes[a]):
                if list_of_cubes[z] <= last_value_placed_on_stack or last_value_placed_on_stack == 0:
                    last_value_placed_on_stack = list_of_cubes[z]
                    list_of_cubes.pop(z)
                    z = z - 1   
                    break
                else:
                    cannot_stack_anymore = True
                    break

    if all_items_on_placed_on_stack:
        print("Yes")
    else:
        print("No")

Friday, April 27, 2018

Computing Fibonacci in Go

Had a coding whiteboard one of my first interviews back in early April.

It's nice to use Go Playground to prove it out and validate it after you get home.

For the whiteboard I had to do it iteratively. I added the recursive func after the fact

Here's the Go Playground link: https://play.golang.org/p/KDQaQlq8ONl

package main

import (
"fmt"
)

func main() {
fmt.Println("Hello, playground. Test for computing Fibonacci numbers")

computeFibonacci(10)
computeFibonacciRecursively(10, 0, 1)
}

func computeFibonacci(numberOfNumbers int) {

penultimate := 0
ultimate := 1

fmt.Printf("\nNext number (iterative): %d", penultimate)
fmt.Printf("\nNext number (iterative): %d", ultimate)

for i := 2; i < numberOfNumbers; i++ {

currentSum := penultimate + ultimate
fmt.Printf("\nNext number (iterative): %d", currentSum)
penultimate = ultimate
ultimate = currentSum

}

}

func computeFibonacciRecursively(numberOfNumbers int, penultimate int, ultimate int) {

if numberOfNumbers == 0 {
return
} else {
fmt.Printf("\nNext number (recurse method): %d", penultimate)
numberOfNumbers--
computeFibonacciRecursively(numberOfNumbers, ultimate, penultimate+ultimate)

}

}

Friday, February 03, 2017

Powershell problem : With remote PSSession, Running EXE in path with spaces and getting back response using Write-Output

I think some of the most trouble I've recently had in coding Powershell has been trying to run an executable on a remote Hyper-V VM that was located under Program Files and then actually getting the response back properly so I could iterate though the results.

The first trickiness was with running the command properly when there were spaces in the path.

In double quotes you have to use the ampersand (&) and then write the path to the EXE in single quotes and then at the end of the string before the closing quotes character, append an argument.

For example :

$commandLocation = "& 'C:\Program Files\....\application_name.exe' argument"

This is the proper syntax that you can then pass to an Invoke-Expression that's inside a ScriptBlock called by Invoke-Command. Invoke-Expression is a very helpful commandlet to run EXEs, when, for example, running Powershell on a remote machine.

The second issue was understanding how I could use Write-Output to pipe the remote call output back a Powershell variable within the ScriptBlock that I could then use in the calling function.

I read that you could use 4>&1 at the end of the ScriptBlock but never found it useful in my case.

In my case, I just had a ScriptBlock assigned to a variable and then ran the ScriptBlock using an Invoke-Command on a separate line.

There was some funkiness with WriteHost appending to the invoke-command so you have to disable that and then return the pure unadulterated Invoke-Command Result that I assigned to a variable.

Then I could iterate over the lines in the method that called the method below.

Here's the example code :

Function RunCommandOnRemoteMachine([string] $blahParameter, [string] $remoteMachineAddress)
{

    $defaultBlahCommandLocation = "& 'C:\Program Files\...\blah.exe' "

    WriteLogAndConsole "Default blah directory : $defaultBlahCommandLocation"
 
    $fullCommand = $defaultBlahCommandLocation +  $blahParameter

    WriteLogAndConsole "Full command with arguments being run : $fullCommand"

    $scriptToExecute = { param($passedCommand)
        begin {
            Write-Host "Start of command:"
        }
        process {
            $consoleOutput = Invoke-Expression -Verbose -Command $passedCommand
        }
        end {
            Write-Host "Output from remote command:"
            Write-Host $consoleOutput
            Write-Host "************"
            Write-Output $consoleOutput
            }
     }

    $blahCommandResult = Invoke-Command -Session $global:session -Verbose -ScriptBlock $scriptToExecute -ArgumentList $fullCommand

    #Write-Host "Result of blah argument command: " $blahCommandResult

    return $blahCommandResult

}

Thursday, January 19, 2017

Powershell New-PS Drive using Administrator credentials. User name or password is incorrect

Sometimes you forget the obvious when your doing scripting.

Although not recommended, I was using powershell to create a new psdrive session using the Administrator.

Problem is that with just Administrator and the password, powershell was complaining about a bad username and password combination.

Since the VM was connected to a development domain I wasn't qualifying the Administrator name therefore confusing powershell.

I add the computername\Administrator and tried again. Much better success

Wednesday, December 21, 2016

Elasticsearch analogies

I work a lot with Elasticsearch.

At my job we have migrated from using SQL Server to Elasticsearch for log storage.

Sometimes, when you're learning new grammar for a new technology you're working on it's nice to have metaphors or similes to use when learning the component parts.

One of the best similies I've heard of for what Elasticsearch represents is that it's like an index at the end of a book. Additionally, Elasticsearch by many, even those who work at Elastic, consider it not a DB.

If you start using Elasticsearch a lot more you'll begin to work with types, templates and mappings.

A type could be analogous to a regular SQL table.

Mappings could be similar to a a table column that stores a field a certain way that could be something like a string, int, varchar.

How mappings and settings are created and loaded has changed from Elasticsearch 1.x to 2.x+. Now that we use Elasticsearch 2.x we have to load template files that are used when new indices are created. They combine settings and the mappings for the fields that get parsed out and placed into an index.

Thanks to this website for giving me those Aha! analogies.

http://swops.com/blog/elasticsearch-mappings-and-templates

Rebuild project of 18 year old Mansfield Toilet

I just completed a toilet rebuild last weekend. The toilet began leaking a year or two ago; especially during warm weather.

Although I wasn't working the whole time the total time from start to finish was a half day. I did initial work and investigations starting Friday night, I let the tank dry out overnight, and I finished about 1 PM the following day having started around 10 AM with the installation of the new parts on the tank.

Actual time working was probably around 4 hours.

Work entailed replacing the fill valve, flush valve, new bolts attaching the tank to the bowl, new shutoff valve and supply line too.





New shutoff valve
New Supply Line to Tank
All parts replaced in dry tank
Tank full with water

All parts were ordered from Mansfield and the cost was just under 50 bucks. I went to Home Depot for the new shutoff valve and supply line.

Total cost was about 60 bucks.

Issues encountered after the replacement was slight leaking from one of the bolts, which I had to tighten down more to prevent further leakage.

As mentioned on my Twitter post, I'd say this home project was a 2-3 out of 10.



Wednesday, July 20, 2016

Perl : subroute redefined, prototype mismatch

I was refactoring my code and placing some common methods into a base module in my Perl lib directory.

Unfortunately some of my new method names had name collisions with possible subroutines in other packages.

I was able to rename the methods that I was exporting for use in my PL files and the errors went away.

Wednesday, March 30, 2016

Python Indentation Error

I've only been using Python for a year.

Before that, my focuses were Java and Perl.

An interesting error I came across, since Python has stricter criteria for formatting was: "IndentationError: expected an indented block"

The code in question:






The error might be considered a red herring since the problem with the else: statement was that there was no real code to run after the if statement.

Once I added a logging statement:






The error went away.