diff --git a/src/main/java/mattrixwv/ProjectEuler/Problems/Problem23.java b/src/main/java/mattrixwv/ProjectEuler/Problems/Problem23.java index 039f996..873396f 100644 --- a/src/main/java/mattrixwv/ProjectEuler/Problems/Problem23.java +++ b/src/main/java/mattrixwv/ProjectEuler/Problems/Problem23.java @@ -1,11 +1,11 @@ -//ProjectEuler/C++/Problem23.java +//ProjectEulerJava/src/main/java/mattrixwv/ProjectEuler/Problems/Problem23.java //Matthew Ellison // Created: 03-22-19 -//Modified: 03-28-19 +//Modified: 06-17-20 //Find the sum of all the positive integers which cannot be written as the sum of two abundant numbers //Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/JavaClasses /* - Copyright (C) 2019 Matthew Ellison + Copyright (C) 2020 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 @@ -30,7 +30,7 @@ import java.util.ArrayList; public class Problem23 extends Problem{ //The largest number to be checked - public static final Integer MAX_NUM = 28123; + public static final int MAX_NUM = 28123; public Problem23(){ super("Find the sum of all the positive integers which cannot be written as the sum of two abundant numbers"); @@ -47,8 +47,9 @@ public class Problem23 extends Problem{ //Start the timer timer.start(); + //Get the sum of the divisors of all numbers < MAX_NUM - for(Integer cnt = 1;cnt.compareTo(MAX_NUM) < 0;++cnt){ + for(int cnt = 1;cnt < MAX_NUM;++cnt){ ArrayList div = Algorithms.getDivisors(cnt); //Remove the last element, which is the number itself. This gives us the propper divisors if(div.size() > 1){ @@ -59,17 +60,17 @@ public class Problem23 extends Problem{ //Get the abundant numbers ArrayList abund = new ArrayList(); - for(Integer cnt = 0;cnt.compareTo(divisorSums.size()) < 0;++cnt){ - if(divisorSums.get(cnt) > cnt.longValue()){ + for(int cnt = 0;cnt < divisorSums.size();++cnt){ + if(divisorSums.get(cnt) > cnt){ abund.add(cnt); } } //Check if each number can be the sum of 2 abundant numbers and add to the sum if no - Long sum = 0L; - for(Integer cnt = 1;cnt.compareTo(MAX_NUM) < 0;++cnt){ + long sum = 0L; + for(int cnt = 1;cnt < MAX_NUM;++cnt){ if(!isSum(abund, cnt)){ - sum += cnt.longValue(); + sum += cnt; } } @@ -80,17 +81,17 @@ public class Problem23 extends Problem{ result = String.format("The answer is %d\n", sum); } //A function that returns true if num can be created by adding two elements from abund and false if it cannot - private Boolean isSum(final ArrayList abund, Integer num){ - Integer sum = 0; + private boolean isSum(final ArrayList abund, int num){ + int sum = 0; //Pick a number for the first part of the sum - for(Integer firstNum = 0;firstNum < abund.size();++firstNum){ + for(int firstNum = 0;firstNum < abund.size();++firstNum){ //Pick a number for the second part of the sum - for(Integer secondNum = firstNum;secondNum < abund.size();++secondNum){ + for(int secondNum = firstNum;secondNum < abund.size();++secondNum){ sum = abund.get(firstNum) + abund.get(secondNum); - if(sum.equals(num)){ + if(sum == num){ return true; } - else if(sum.compareTo(num) > 0){ + else if(sum > num){ break; } } @@ -102,5 +103,5 @@ public class Problem23 extends Problem{ /* Results: The answer is 4179871 -It took 49.791 seconds to solve this problem. +It took 12.277 seconds to solve this problem. */