My beginnings in C++

This semester (my final semester at VCU), I am taking INFO 450: Advanced Programming, which concentrates in C++. We're learning both native and managed C++. Our first assignment was simple: a console application to calculate the monthly payments on a car loan, based on interest rate, total loan, and loan duration. That was pretty easy.

This assignment was pretty rough. We had to code a fully functional ATM application, which uses a hardcoded bank database, accounts, authentication, withdrawal & deposit simulation, etc. We were told that we could mirror the ATM case study at the end of our Learn to Program C# 2005 by Deitel (the book from intermediate programming).

After mirroring the C# code, I kept getting error after error. It was ridiculous how every error stemmed from how header files were used in my code. Eventually, I worked out the problems with the header files. Then, I kept getting this compiler error: LNK2019. I searched and searched online, and couldn't find a suitable answer. Finally, I retraced all my code, and realized that I had three classes (Withdrawal, Deposit, BalanceInquiry) all overriding the virtual function 'Execute' from class Transaction, but that class wasn't marked virtual. This probably should have been the first place I looked, but keep in mind we were given this assignment the day after we learned about references.

To make a long story short, I was receiving LNK2019 errors because of my virtual functions. The error was caused by declaring the function as "virtual void Execute();" instead of "virtual void Execute() = 0;" Embarrassingly, that little mistake took me forever to figure out. I somewhat hope that whatever path I take in the future uses tools with less cryptic error messages.

C# Insertion Sorting algorithm

Here is a console application to test an Insertion Sorting algorithm adapted from chapter 2 of MIT's Introduction to Algorithms. I thought this might come in handy for any beginners, as well as a fun way to test your computer's performance.
My desktop averages about 24.9 seconds, which, of course, depends on how scattered the integers are in the array.

   1:  using System;

   2:  using System.Collections.Generic;

   3:  using System.Linq;

   4:  using System.Text;

   5:   

   6:  namespace InsertionSorting

   7:  {

   8:      class Program

   9:      {

  10:          static void Main(string[] args)

  11:          {

  12:              // int[] A = {5, 2, 4, 6, 1, 3};

  13:              int initializer = 100000;

  14:              int[] A = new int[initializer];

  15:   

  16:              for (int c = 0; c < A.Length; c++)

  17:              {

  18:                  A[c] = c;

  19:              }

  20:   

  21:              // Random shuffle

  22:              Random rand = new Random();

  23:              for (int d = 0; d < A.Length; d++)

  24:              {

  25:                  int firstInt = A[d];

  26:                  int swapIndex = rand.Next(initializer);

  27:                  int secondInt = A[swapIndex];

  28:   

  29:                  A[d] = secondInt;

  30:                  A[swapIndex] = firstInt;

  31:              }

  32:              

  33:              //Console.Write("Array before sorting: ");

  34:              //foreach (int number in A)

  35:              //{

  36:              //    Console.Write("{0} ", number);

  37:              //}

  38:              //Console.WriteLine("");

  39:   

  40:              int key;

  41:              int i;

  42:              int j;

  43:   

  44:              Console.Write("Insertion Sorting array of {0} numbers, please wait...", initializer);

  45:              

  46:              DateTime start = DateTime.Now;

  47:              for (j = 1; j < A.Length; j++)

  48:              {

  49:                  key = A[j];

  50:                  i = j;

  51:   

  52:                  while (i > 0 && A[i - 1] > key)

  53:                  {                    

  54:                      A[i] = A[i-1];

  55:                      i--;

  56:                  };

  57:                  

  58:                  A[i] = key;

  59:              }

  60:              DateTime finish = DateTime.Now;

  61:              

  62:              //Console.Write("Array after sorting: ");

  63:              //foreach (int number in A)

  64:              //{

  65:              //    Console.Write("{0} ", number);

  66:              //}

  67:   

  68:              Console.WriteLine("");

  69:              Console.WriteLine("Duration: {0} seconds", (finish - start).ToString());

  70:          }

  71:      }

  72:  }

  73: