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ProjectEulerCS/ProjectEulerCS/Problems/Problem1.cs

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2.8 KiB
C#

//ProjectEuler/ProjectEulerCS/src/Problems/Problem1.cs
//Matthew Ellison
// Created: 08-14-20
//Modified: 07-05-21
//What is the sum of all the multiples of 3 or 5 that are less than 1000
//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/CSClasses
/*
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/>.
*/
using System;
namespace ProjectEulerCS.Problems{
public class Problem1 : Problem{
//Variables
//Static variables
private const int TOP_NUM = 999; //The largest number to tbe checked
//Instance variables
private int fullSum; //The sum of all the numbers
public int Sum{
get{
SolvedCheck("sum");
return fullSum;
}
}
//The results of the problem
public override string Result{
get{
SolvedCheck("result");
return $"The sum of all numbers < {TOP_NUM + 1} is {fullSum}";
}
}
//Functions
//Constructor
public Problem1() : base($"What is the sum of all the multiples of 3 or 5 that are less than {TOP_NUM + 1}"){
fullSum = 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();
//Get the sum of the progressions of 3 and 5 and remove the sum of progressions of the overlap
fullSum = SumOfProgression(3) + SumOfProgression(5) - SumOfProgression(3 * 5);
//Stop the timer
timer.Stop();
//Thow a flag to show the problem is solved
solved = true;
}
//Reset the problem so it can be run again
public override void Reset(){
base.Reset();
fullSum = 0;
}
private int SumOfProgression(double multiple){
double numTerms = Math.Floor(TOP_NUM / multiple); //This gets the number of multiples of a particular number that is < MAX_NUMBER
//The sum of progression formula is (n / 2)(a + l). n = number of terms, a = multiple, l = last term
return (int)(numTerms / 2.0 * (multiple + (numTerms * multiple)));
}
}
}
/* Results:
The sum of all numbers < 1000 is 233168
It took an average of 1.351 microseconds to run this problem through 100 iterations
*/