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Updated for performance

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Mattrixwv
2020-06-17 22:29:03 -04:00
parent f664a076a6
commit 64f43e0a4d
1 changed files with 18 additions and 18 deletions
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src/main/java/mattrixwv/ProjectEuler/Problems/Problem28.java
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@@ -1,11 +1,11 @@
//ProjectEuler/Java/Problem28.java //ProjectEulerJava/src/main/java/mattrixwv/ProjectEuler/Problems/Problem28.java
//Matthew Ellison //Matthew Ellison
// Created: 09-22-19 // Created: 09-22-19
//Modified: 09-22-19 //Modified: 06-17-20
//What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed by starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral //What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed by starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral
//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/JavaClasses //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 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 it under the terms of the GNU Lesser General Public License as published by
@@ -30,7 +30,7 @@ public class Problem28 extends Problem{
//Holds the grid that we will be filling and searching //Holds the grid that we will be filling and searching
private static ArrayList<ArrayList<Integer>> grid; private static ArrayList<ArrayList<Integer>> grid;
//Holds the sum of the diagonals of the grid //Holds the sum of the diagonals of the grid
private Integer sumOfDiagonals = 0; private int sumOfDiagonals = 0;
public Problem28(){ public Problem28(){
super("What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed by starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral"); super("What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed by starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral");
@@ -39,20 +39,20 @@ public class Problem28 extends Problem{
private void setupGrid(){ private void setupGrid(){
grid = new ArrayList<ArrayList<Integer>>(); grid = new ArrayList<ArrayList<Integer>>();
//Fill the grid with 0's //Fill the grid with 0's
for(Integer cnt = 0;cnt < 1001;++cnt){ for(int cnt = 0;cnt < 1001;++cnt){
//Add a blank ArrayList //Add a blank ArrayList
grid.add(new ArrayList<Integer>()); grid.add(new ArrayList<Integer>());
for(Integer cnt2 = 0;cnt2 < 1001;++cnt2){ for(int cnt2 = 0;cnt2 < 1001;++cnt2){
grid.get(cnt).add(0); grid.get(cnt).add(0);
} }
} }
Boolean finalLocation = false; //A flag to indicate if the final location to be filled has been reached boolean finalLocation = false; //A flag to indicate if the final location to be filled has been reached
//Set the number that is going to be put at each location //Set the number that is going to be put at each location
Integer currentNum = 1; int currentNum = 1;
//Start with the middle location and set it correctly and advance the tracker to the next number //Start with the middle location and set it correctly and advance the tracker to the next number
Integer xLocation = 500; int xLocation = 500;
Integer yLocation = 500; int yLocation = 500;
grid.get(yLocation).set(xLocation, currentNum++); grid.get(yLocation).set(xLocation, currentNum++);
//Move right the first time //Move right the first time
++xLocation; ++xLocation;
@@ -81,22 +81,22 @@ public class Problem28 extends Problem{
grid.get(yLocation).set(xLocation, currentNum++); grid.get(yLocation).set(xLocation, currentNum++);
++xLocation; ++xLocation;
//Check if you are at the final location and break the loop if you are //Check if you are at the final location and break the loop if you are
if(xLocation.equals(grid.size())){ if(xLocation == grid.size()){
finalLocation = true; finalLocation = true;
break; break;
} }
} }
} }
} }
//Finds the sum of teh diagonals in the grid //Finds the sum of the diagonals in the grid
private void findSum(){ private void findSum(){
//Start at teh top corners and work your way down moving toward the opposite side //Start at the top corners and work your way down moving toward the opposite side
Integer leftSide = 0; int leftSide = 0;
Integer rightSide = grid.size() - 1; int rightSide = grid.size() - 1;
Integer row = 0; int row = 0;
while(row < grid.size()){ while(row < grid.size()){
//This ensures the middle location is only counted once //This ensures the middle location is only counted once
if(Integer.compare(leftSide, rightSide) == 0){ if(leftSide == rightSide){
sumOfDiagonals += grid.get(row).get(leftSide); sumOfDiagonals += grid.get(row).get(leftSide);
} }
else{ else{
@@ -127,5 +127,5 @@ public class Problem28 extends Problem{
/* Results: /* Results:
The sum of the diagonals in the given grid is 669171001 The sum of the diagonals in the given grid is 669171001
It took 84.535 milliseconds to solve this problem. It took 16.687 milliseconds to solve this problem.
*/ */