Added solution to problem 6

ProjectEulerCS/ProblemSelection.cs

@@ -30,7 +30,7 @@ namespace ProjectEulerCS{
 	public class ProblemSelection{
 		//Holds the valid problem numbers
 		private static readonly List<int> _PROBLEM_NUMBERS = new List<int>()
-				{0, 1, 2, 3, 4, 5};
+				{0, 1, 2, 3, 4, 5, 6};
 		public static System.Collections.Generic.List<int> PROBLEM_NUMBERS{
 			get { return _PROBLEM_NUMBERS; }
 		}
@@ -44,6 +44,7 @@ namespace ProjectEulerCS{
 				case 3: problem = new Problem3(); break;
 				case 4: problem = new Problem4(); break;
 				case 5: problem = new Problem5(); break;
+				case 6: problem = new Problem6(); break;
 			}
 			return problem;
 		}

ProjectEulerCS/Problems/Problem6.cs

@@ -0,0 +1,105 @@
+//ProjectEuler/ProjectEulerCS/src/Problems/Problem6.cs
+//Matthew Ellison
+// Created: 08-23-20
+//Modified: 08-23-20
+//Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.
+//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/CSClasses
+/*
+	Copyright (C) 2020  Matthew Ellison
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Lesser General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU Lesser General Public License for more details.
+
+	You should have received a copy of the GNU Lesser General Public License
+	along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+
+namespace ProjectEulerCS.Problems{
+	public class Problem6 : Problem{
+		//Variables
+		//Static variables
+		private const int START_NUM = 1;	//The first number that needs to be counted
+		private const int END_NUM = 100;	//The last number that needs to be counted
+		//Instance variables
+		private long _sumOfSquares;	//Holds the sum of the squares of all the numbers
+		public long sumOfSquares{
+			get{
+				if(!solved){
+					throw new Unsolved();
+				}
+				return _sumOfSquares;
+			}
+		}
+		private long _squareOfSum;	//Holds the square of the sum of all the numbers
+		public long squareOfSum{
+			get{
+				if(!solved){
+					throw new Unsolved();
+				}
+				return _squareOfSum;
+			}
+		}
+		public long difference{
+			get{
+				if(!solved){
+					throw new Unsolved();
+				}
+				return System.Math.Abs(_sumOfSquares - _squareOfSum);
+			}
+		}
+
+		//Functions
+		//Constructor
+		public Problem6() : base("Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum."){
+			_sumOfSquares = 0;
+			_squareOfSum = 0;
+		}
+		//Operational functions
+		//Solve the problem
+		public override void solve(){
+			//If the problem has already been solved do nothing and end the function
+			if(solved){
+				return;
+			}
+
+			//Start the timer
+			_timer.start();
+
+			//Run through all numbers and add them to the appropriate sums
+			for(int currentNum = START_NUM;currentNum <= END_NUM;++currentNum){
+				_sumOfSquares += (currentNum * currentNum);	//Add the square to the correct variable
+				_squareOfSum += currentNum;	//Add the number to the correct variable to squaring later
+			}
+			//Squaring the sum that needs it
+			_squareOfSum *= _squareOfSum;
+
+			//Stop the timer
+			_timer.stop();
+
+			//Throw a flag to show the problem is solved
+			solved = true;
+
+			//Save the results
+			_result = "The difference between the sum of the squares and the square of the sum of all numbers from 1-100 is " + System.Math.Abs(_sumOfSquares - _squareOfSum);
+		}
+		//Reset the problem so it can be run again
+		public override void reset(){
+			base.reset();
+			_squareOfSum = 0;
+			_sumOfSquares = 0;
+		}
+	}
+}
+
+/* Results:
+The difference between the sum of the squares and the square of the sum of all numbers from 1-100 is 25164150
+It took an average of 234.000 nanoseconds to run this problem through 100 iterations
+*/