Added solution to problem 28

ProblemSelection.ts

@@ -51,12 +51,13 @@ import { Problem24 } from "./Problems/Problem24";
 import { Problem25 } from "./Problems/Problem25";
 import { Problem26 } from "./Problems/Problem26";
 import { Problem27 } from "./Problems/Problem27";
+import { Problem28 } from "./Problems/Problem28";
 
 
 export class ProblemSelection{
 	//Holds the valid problem numbers
 	public static PROBLEM_NUMBERS: number[] = [  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
-												21, 22, 23, 24, 25, 26, 27];
+												21, 22, 23, 24, 25, 26, 27, 28];
 
 	//Returns the problem corresponding to the given problem number
 	public static getProblem(problemNumber: number): Problem{
@@ -89,6 +90,7 @@ export class ProblemSelection{
 			case 25: problem = new Problem25(); break;
 			case 26: problem = new Problem26(); break;
 			case 27: problem = new Problem27(); break;
+			case 28: problem = new Problem28(); break;
 		}
 		return problem;
 	}

Problems/Problem28.ts

@@ -0,0 +1,170 @@
+//ProjectEulerTS/Problems/Problem27.ts
+//Matthew Ellison
+// Created: 05-26-21
+//Modified: 05-26-21
+//What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed by starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral
+//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/typescriptClasses
+/*
+	Copyright (C) 2021  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/>.
+*/
+
+
+import { Unsolved } from "../Unsolved";
+import { Problem } from "./Problem";
+
+
+export class Problem28 extends Problem{
+	//Variables
+	//Static variables
+	private static grid: number[][];	//Holds the grid that we will be filling and searching
+	//Instance variables
+	private sumOfDiagonals: number;	//Holds the sum of the diagonals of the grid
+
+	//Functions
+	//Constructor
+	public constructor(){
+		super(`What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed by starting with the number 1 and moving to the right in a clockwise diration`);
+		this.sumOfDiagonals = 0;
+	}
+	//Operational functions
+	//Sets up the grid
+	private setupGrid(): void{
+		Problem28.grid = [];
+		//Fill the grid with 0's
+		for(let cnt = 0;cnt < 1001;++cnt){
+			Problem28.grid.push([]);
+			for(let cnt2 = 0;cnt2 < 1001;++cnt2){
+				Problem28.grid[cnt].push(0);
+			}
+		}
+
+		let finalLocation: boolean = false;	//A flag to indicate if the final location to be filled has been reached
+		//Set the number that is going to be put at each location
+		let currentNum: number = 1;
+		//Start with the middle location and set it correctly and advance the tracker to the next number
+		let xLocation: number = 500;
+		let yLocation: number = 500;
+		Problem28.grid[yLocation][xLocation] = currentNum++;
+		//Move right the first time
+		++xLocation;
+		//Move in a circular pattern until you rach the final location
+		while(!finalLocation){
+			//Move down until you reach a blank location on the left
+			while(Problem28.grid[yLocation][xLocation - 1] != 0){
+				Problem28.grid[yLocation][xLocation] = currentNum++;
+				++yLocation;
+			}
+
+			//Move left until you reach a blank location above
+			while(Problem28.grid[yLocation - 1][xLocation] != 0){
+				Problem28.grid[yLocation][xLocation] = currentNum++;
+				--xLocation;
+			}
+
+			//Move up until you reach a blank location to the right
+			while(Problem28.grid[yLocation][xLocation + 1] != 0){
+				Problem28.grid[yLocation][xLocation] = currentNum++;
+				--yLocation;
+			}
+
+			//Move right until you reach a blank location below
+			while(Problem28.grid[yLocation + 1][xLocation] != 0){
+				Problem28.grid[yLocation][xLocation] = currentNum++;
+				++xLocation;
+				//Check if you are at the final location and break the loop if you are
+				if(xLocation == Problem28.grid.length){
+					finalLocation = true;
+					break;
+				}
+			}
+		}
+	}
+	//Finds the sum of the diagonals in the grid
+	private findSum(): void{
+		//Start at the top corners and work your way down moving toward the opposite side
+		let leftSide: number = 0;
+		let rightSide: number = Problem28.grid.length - 1;
+		let row: number = 0;
+		while(row < Problem28.grid.length){
+			//This ensures the middle location is only counted once
+			if(leftSide == rightSide){
+				this.sumOfDiagonals += Problem28.grid[row][leftSide];
+			}
+			else{
+				this.sumOfDiagonals += Problem28.grid[row][leftSide];
+				this.sumOfDiagonals += Problem28.grid[row][rightSide];
+			}
+			++row;
+			++leftSide;
+			--rightSide;
+		}
+	}
+	//Solve the problem
+	public solve(): void{
+		//If the problem has already been solved do nothing and end the function
+		if(this.solved){
+			return;
+		}
+
+		//Start the timer
+		this.timer.start();
+
+		//Setup the grid
+		this.setupGrid();
+		//FInd the sum of the diagonals in the grid
+		this.findSum();
+
+		//Stop the timer
+		this.timer.stop();
+
+		//Throw a flag to show the problem is solved
+		this.solved = true;
+	}
+	//Reset the problem so it can be run again
+	public reset(): void{
+		super.reset();
+		this.sumOfDiagonals = 0;
+	}
+	//Gets
+	//Returns the result of solving the problem
+	public getResult(): string{
+		if(!this.solved){
+			throw new Unsolved();
+		}
+		return `The sum of the diagonals in the given grid is ${this.sumOfDiagonals}`;
+	}
+	//Returns the grid
+	public getGrid(): number[][]{
+		//IF the problem hasn't been solved throw an exception
+		if(!this.solved){
+			throw new Unsolved();
+		}
+		return Problem28.grid;
+	}
+	//Returns the sum of the diagonals
+	public getSum(): number{
+		//If the problem hasn't been solved throw an exception
+		if(!this.solved){
+			throw new Unsolved();
+		}
+		return this.sumOfDiagonals;
+	}
+}
+
+/* Results:
+The sum of the diagonals in the given grid is 669171001
+It took an average of 16.924 milliseconds to run this problem through 100 iterations
+*/