ProjectEulerTS/Problems/Problem17.ts

//ProjectEulerTS/Problems/Problem17.ts
//Matthew Ellison
// Created: 03-29-21
//Modified: 07-14-21
//If all the numbers from 1 to 1000 (one thousand) inclusive were written out in words, how many letters would be used?
//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 Problem17 extends Problem{
	//Variables
	//Static variables
	private static START_NUM: number = 1;	//This is the smallest number to get the words of
	private static STOP_NUM: number = 1000;	//This is the largest number to get the words of
	//Instance variables
	private letterCount: number;	//This is the cumulative number of letters in the words of the numbers

	//Functions
	//Constructor
	public constructor(){
		super(`If all of teh numbers from ${Problem17.START_NUM} to ${Problem17.STOP_NUM} inclusive were written out in words, how many letters would be used?`);
		this.letterCount = 0;
	}
	//Operational functions
	//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();


		//Start with 1 and increment
		for(let num: number = Problem17.START_NUM;num <= Problem17.STOP_NUM;++num){
			//Pass the number to a function that will create a string for the number
			let currentNumString: string = this.makeWordFromNum(num);
			//Pass the string to the function that will count the number of letters in it, ignoring whitespace and punctuation and add that number to the running tally
			this.letterCount += this.getNumberChars(currentNumString);
		}


		//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.letterCount = 0;
	}
	//This function makes a word out of the number passed into it
	private makeWordFromNum(orgNum: number): string{
		let num: number = orgNum;
		let numberString: string = "";
		//Starting with the largest digit create a string based on the number passed in
		//Check for negative
		if(num < 0){
			numberString += "negative ";
		}

		//Check if the number is zero
		if(num == 0){
			numberString += "zero";
		}

		//Start with the thousands place
		if((num / 1000) >= 1){
			numberString += this.makeWordFromNum(Math.floor(num / 1000));
			numberString += " thousand";
			num -= (Math.floor(num / 1000) * 1000);
		}

		//Check the hundreds place
		if((num / 100) >= 1){
			numberString += this.makeWordFromNum(Math.floor(num / 100));
			numberString += " hundred";
			num -= (Math.floor(num / 100) * 100);
		}

		//Insert an and if there is need
		if((numberString.trim().length > 0) && (num > 0)){
			numberString += " and ";
		}

		//Check for tens place
		if((num / 10) >= 2){
			//For the tens you need to do something special
			let tensPlace: number = Math.floor(num / 10);
			switch(tensPlace){
				case 9: numberString += "ninety"; break;
				case 8: numberString += "eighty"; break;
				case 7: numberString += "seventy"; break;
				case 6: numberString += "sixty"; break;
				case 5: numberString += "fifty"; break;
				case 4: numberString += "forty"; break;
				case 3: numberString += "thirty"; break;
				case 2: numberString += "twenty"; break;
			}
			num -= (tensPlace * 10);
			//If there is something left in the number you will need a dash to separate the tens and ones place
			if(num > 0){
				numberString += "-";
			}
		}
		//Check for teens
		else if((num / 10) >= 1){
			let onesPlace: number = (num % 10);
			switch(onesPlace){
				case 9: numberString += "nineteen"; break;
				case 8: numberString += "eighteen"; break;
				case 7: numberString += "seventeen"; break;
				case 6: numberString += "sixteen"; break;
				case 5: numberString += "fifteen"; break;
				case 4: numberString += "fourteen"; break;
				case 3: numberString += "thirteen"; break;
				case 2: numberString += "twelve"; break;
				case 1: numberString += "eleven"; break;
				case 0: numberString += "ten"; break;
			}
			//If this was hit the number was completed
			num = 0;
		}

		//Check for the ones place
		if(num >= 1){
			switch(num){
				case 9: numberString += "nine"; break;
				case 8: numberString += "eight"; break;
				case 7: numberString += "seven"; break;
				case 6: numberString += "six"; break;
				case 5: numberString += "five"; break;
				case 4: numberString += "four"; break;
				case 3: numberString += "three"; break;
				case 2: numberString += "two"; break;
				case 1: numberString += "one"; break;
			}
			//If this was hit the number was completed
			num = 0;
		}

		//If the number is not 0 there was a problem
		if(num != 0){
			throw new Unsolved("The number " + orgNum + " was not completely reduced!\nRemainder is " + num);
		}

		//Return the string
		return numberString;
	}
	//This counts the number of letters in the string that is passed in (ignoring numbers and puctuation)
	private getNumberChars(num: string): number{
		let sumOfLetters: number = 0;
		//Start at location 0 and count the number of letters, ignoring punctuation and whitespace
		for(let location: number = 0;location < num.length;++location){
			let char = num.charAt(location).toLowerCase();
			if((char >= "a") && (char <= "z")){
				sumOfLetters += 1;
			}
		}

		//Returns the number of letters
		return sumOfLetters;
	}
	//Gets
	//Returns the result of solving the problem
	public getResult(): string{
		this.solvedCheck("result");
		return `The sum of all the letters in all the numbers ${Problem17.START_NUM}-${Problem17.STOP_NUM} is ${this.letterCount}`;
	}
	//Returns the number of letters asked for
	public getLetterCount(): number{
		this.solvedCheck("letter count");
		return this.letterCount;
	}
}


/* Results:
The sum of all the letters in all the numbers 1-1000 is 21124
It took an average of 485.744 microseconds to run this problem through 100 iterations
*/