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ProjectEulerTS/Problems/Problem34.ts

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TypeScript

//ProjectEulerTS/Problems/Problem34.ts
//Matthew Ellison
// Created: 06-01-21
//Modified: 07-14-21
//Find the sum of all numbers which are equal to the sum of the factorial of their digits
//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 { factorial } from "../../../Typescript/typescriptClasses/NumberAlgorithms";
import { Problem } from "./Problem";
export class Problem34 extends Problem{
//Variables
//Static variables
private static MAX_NUM: number = 1499999; //The largest num that can be the sum of its own digits
//Instance variables
private factorials: number[]; //Holds the pre-computed factorials of the numbers 0-9
private sum: number; //Holds the sum of all numbers equal to the sum of their digit's factorials
//Functions
//Constructor
public constructor(){
super("Find the sum of all numbers which are equal to the sum of the factorial of their digits");
this.sum = 0;
this.factorials = [];
for(let cnt = 0;cnt <= 9;++cnt){
this.factorials.push(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();
//Pre-compute the possible factorials form 0! to 9!
for(let cnt = 0;cnt <= 9;++cnt){
this.factorials[cnt] = factorial(cnt);
}
//Run through all possible numbers from 3-MAX_NUM and see if they equal the sum of their digit's factorials
for(let cnt = 3;cnt < Problem34.MAX_NUM;++cnt){
//Split the number into tis digits and add each one to the sum
let numString: string = cnt.toString();
let currentSum: number = 0;
for(let numCnt = 0;numCnt < numString.length;++numCnt){
let digit = numString.charAt(numCnt);
currentSum += this.factorials[parseInt(digit)];
}
//If the number is equal to the sum add the sum to the running sum
if(currentSum == cnt){
this.sum += currentSum;
}
}
//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.sum = 0;
this.factorials = [];
for(let cnt = 0;cnt <= 9;++cnt){
this.factorials.push(0);
}
}
//Gets
//Returns the result of solving the problem
public getResult(): string{
this.solvedCheck("result");
return `The sum of all numbers that are the sum of their digit's factorials is ${this.sum}`;
}
//Returns the list of factorials from 0-9
public getFactorials(): number[]{
this.solvedCheck("list of factorials");
return this.factorials;
}
//Returns the sum of all numbers equal to the sum of their digit's factorials
public getSum(): number{
this.solvedCheck("sum");
return this.sum;
}
}
/* Results:
The sum of all numbers that are the sum of their digit's factorials is 40730
It took an average of 87.615 milliseconds to run this problem through 100 iterations
*/