From a205fbfd0c41cde05de640a9a110f8709810a4ed Mon Sep 17 00:00:00 2001 From: Mattrixwv Date: Mon, 26 Oct 2020 14:44:44 -0400 Subject: [PATCH] Updated problem 1 algorithm --- Problem1.lua | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/Problem1.lua b/Problem1.lua index 47db185..a22c64d 100644 --- a/Problem1.lua +++ b/Problem1.lua @@ -1,7 +1,7 @@ --ProjectEuler/lua/Problem1.lua --Matthew Ellison -- Created: 02-01-19 ---Modified: 06-19-20 +--Modified: 10-26-20 --What is the sum of all the multiples of 3 or 5 that are less than 1000 --All of my requires, unless otherwise listed, can be found at https://bitbucket.org/Mattrixwv/luaClasses --[[ @@ -25,19 +25,23 @@ require "Stopwatch" +local TOP_NUMBER = 999; --This is the largest number that you are going to check +local sumOfMultiples = 0; + + local timer = Stopwatch:create(); timer:start(); -local TOP_NUMBER = 999; --This is the largest number that you are going to check -local sumOfMultiples = 0; -for num = 1, TOP_NUMBER do - if((num % 3) == 0) then - sumOfMultiples = sumOfMultiples + num; - elseif((num % 5) == 0) then - sumOfMultiples = sumOfMultiples + num; - end +--Gets the sum of the progression of the multiple +local function sumOfProgression(multiple) + local numTerms = TOP_NUMBER // 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 ((numTerms / 2) * (multiple + (numTerms * multiple))); end +--Get the sum of the progressions of 3 and 5 and remove the sum of progressions of the overlap +sumOfMultiples = math.floor(sumOfProgression(3)) + math.floor(sumOfProgression(5)) - math.floor(sumOfProgression(3 * 5)); + timer:stop() --Print the results @@ -47,5 +51,5 @@ print("It took " .. timer:getMicroseconds() .. " microseconds to run this algori --[[Results: The sum of all numbers < 1000 is 233168 -It took 148 microseconds to run this algorithm +It took 2.0 microseconds to run this algorithm ]]