iamchung

So I’ve decided to start up yet another web project to add to my already long list of unfinished items hidden away in my digital repository closet. This time the language is php and I thought we could try out something new. For the project, I’m basically creating a custom CMS to show article-style pages along with a search feature. My experience with Zend Studio was a favorable one so it will be interesting to see how much of it was due to Zend and how much was due to Eclipse (Aptana is also an Eclipse-based IDE). I’ve also heard netBeans is a good alternative php IDE but I haven’t tried it yet. I’ll be posting again soon with my impressions.

Check Aptana out here

programming aptana, eclipse, php

As a way to get reacquainted with c++, I’m revisiting all my PE problems.  Here’s the code for #1.

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Find the sum of all the multiples of 3 or 5 below 1000.

#include <iostream>

int main(int argc, char* argv[])
{
    int iMax = 1000;
    int iSum = 0;
    int iMultiplesOf[2] = { 3, 5 };
    for each (int iNum in iMultiplesOf)
    {
        for (int i = 0; i * iNum < iMax; i++)
        {
            iSum += i * iNum;
        }
    }
    std::cout << iSum << std::endl;
    system("PAUSE");
    return 0;
}

programming c++, project euler

Project Euler has quickly become my hobby for when I have small moments of free time.  Here is problem #7:

Public Sub GetPrime()
    Dim iPrimeMax As Integer = 10001
    Dim iPrimeCounter As Integer = 0
    Dim iCurrentNum As Integer = 2
    While (iPrimeCounter < iPrimeMax)
        Dim bPrime As Boolean = True
        Dim iCounter As Integer = 1
        While (bPrime = True And iCounter < iCurrentNum)
            If (iCurrentNum Mod iCounter = 0 And iCounter <> 1) Then
                bPrime = False
            End If
            iCounter += 1
        End While
        If (bPrime = True) Then
            iPrimeCounter += 1
        End If
        iCurrentNum += 1
    End While
    Response.Write((iCurrentNum - 1).ToString())
End Sub

programming prime number, project euler

The problem:

Public Sub Difference()
    Dim iStart, iEnd, iSumOfSquares, iSquareOfSum As Integer
    iStart = 1
    iEnd = 100
    iSumOfSquares = 0
    iSquareOfSum = 0

    For iCounter As Integer = iStart To iEnd
        iSumOfSquares = iSumOfSquares + iCounter ^ 2
        iSquareOfSum = iSquareOfSum + iCounter
    Next

    Response.Write(iSquareOfSum ^ 2 - iSumOfSquares)
End Sub

programming project euler, square of sum, sum of squares

Project Euler problem #4:

Public Sub Palindrome()
    Dim iMax As Integer = 999
    Dim iX, iY, iProduct, iStart, iEnd, iLargest As Integer
    iLargest = 0
    Dim bFound As Boolean = False
    For iX = 100 To iMax
        For iY = 100 To iMax
            iProduct = iX * iY
            Dim sProduct As String = iProduct.ToString()
            iStart = 0
            iEnd = sProduct.Length - 1
            Dim bStop As Boolean = False
            While (iStart + 1 <= iEnd And bStop = False)
                If (sProduct(iStart) <> sProduct(iEnd)) Then
                    bStop = True
                End If
                iStart = iStart + 1
                iEnd = iEnd - 1
            End While
            If (bStop = False) Then
                If (iProduct > iLargest) Then
                    iLargest = iProduct
                End If
            End If
        Next
    Next
    Response.Write(iLargest.ToString())
End Sub

programming palindrome, project euler

projecteuler.net is one of my new favorite addictions.  i’ll be periodically posting my solutions to the problems on this site to keep track of my algorithms.  this is problem #2:

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, …

Find the sum of all the even-valued terms in the sequence which do not exceed four million.

and this is my brute force solution done in asp.net:

protected void Page_Load(object sender, EventArgs e)
{
	long prevFib = 0;
	long currFib = 1;
	long sum = 0;
	while (currFib < 4000000)
	{
		if (currFib % 2 == 0)
		{
			sum += currFib;
		}
		currFib += prevFib;
		prevFib = currFib - prevFib;
	}
	Response.Write(sum.ToString());
}

this is problem #3:

The prime factors of 13195 are 5, 7, 13 and 29.

What is the largest prime factor of the number 600851475143 ?

and this is my solution which started off brute force but reduces the target number every time it finds a new prime factor causing a drastic reduction in processing time:

protected void Page_Load(object sender, EventArgs e)
{
	long target = 600851475143;
	for (long counter = 2; counter < target; counter++)
	{
		// is counter a factor?
		if (target % counter == 0)
		{
			// find out if counter is prime
			bool print = true;
			for (long i = 2; i < counter; i++)
			{
				// if counter isn't prime,
				// cut out of for-loop and don't print
				if (counter % i == 0)
				{
					i = counter;
					print = false;
				}
			}
			if (print)
			{
				Response.Write(counter.ToString() + "<br/>");
				// counter is a prime factor.  let's divide target
				// by counter to get a smaller target to work with.
				target = target / counter;
			}
		}
	}
	Response.Write(target.ToString());
}

programming math, project euler

So I’m doing this XML to wordML conversion using XSLT and there is this annoying blank page at the end of my document.  My code looks like this:

<w:body>
   <wx:sect>
      <w:p>
         <w:pPr>
            <w:sectPr>
               <w:type w:val="continuous"/>
            </w:sectPr>
         </w:pPr>
         <w:r>
            <w:t>section 1</w:t>
         </w:r>
      </w:p>
   </wx:sect>
   <wx:sect>
      <w:p>
         <w:pPr>
            <w:sectPr>
               <w:type w:val="continuous"/>
            </w:sectPr>
         </w:pPr>
         <w:r>
            <w:t>section 2</w:t>
         </w:r>
      </w:p>
   </wx:sect>
</w:body>

However, all you have to do to avoid the blank page is move the section formatting information from inside the last paragraph of the last section to a sibling node next to the last paragraph node.

<w:body>
   <wx:sect>
      <w:p>
         <w:pPr>
            <w:sectPr>
               <w:type w:val="continuous"/>
            </w:sectPr>
         </w:pPr>
         <w:r>
            <w:t>section 1</w:t>
         </w:r>
      </w:p>
   </wx:sect>
   <wx:sect>
      <w:p>
         <w:pPr>
         </w:pPr>
         <w:r>
            <w:t>section 2</w:t>
         </w:r>
      </w:p>
      <w:sectPr>
         <w:type w:val="continuous"/>
      </w:sectPr>
   </wx:sect>
</w:body>

Tada! Blank page gone and your document still has excellent structure.

programming blank page, wordml, xsl