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https://bitbucket.org/Mattrixwv/projecteulerlua.git
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66 lines
2.1 KiB
Lua
66 lines
2.1 KiB
Lua
--ProjectEUler/lua/Problem12.lua
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--Matthew Ellison
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-- Created: 02-07-19
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--Modified: 03-28-19
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--What is the value of the first triangle number to have over five hundred divisors?
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--All of my requires, unless otherwise listed, can be found at https://bitbucket.org/Mattrixwv/luaClasses
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--[[
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Copyright (C) 2019 Matthew Ellison
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>.
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]]
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require "Stopwatch"
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require "Algorithms"
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timer = Stopwatch:create();
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timer:start();
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GOAL_DIVISORS = 500;
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local triangularNumber = 1;
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local nextNumber = 2;
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local foundNumber = false;
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local divisors = {};
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while((not foundNumber) and (triangularNumber > 0)) do
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--See how many divisors this triangular number has
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divisors = getDivisors(triangularNumber);
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--If it has more than GOAL_DIVISORS raise a flag to stop the loop
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if(#divisors > GOAL_DIVISORS) then
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foundNumber = true;
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else
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triangularNumber = triangularNumber + nextNumber; --Add the next number to continue the triangular sequence
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nextNumber = nextNumber + 1; --Advance to the next number for the triangular sequence
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end
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end
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timer:stop();
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--Print the results
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if(foundNumber) then
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print("The first triangular number with more than " .. GOAL_DIVISORS .. " divisors is " .. triangularNumber);
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else
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print("There was an error. Could not find a triangular number with " .. GOAL_DIVISORS .. " divisors before overflow");
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end
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print("It took " .. timer:getSeconds() .. " seconds to run this algorithm");
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--[[Results
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The first triangular number with more than 500divisors is 76576500
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It took 1.498547 seconds to run this algorithm
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]]
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