Files
ProjectEulerJava/Problem11.java

191 lines
8.3 KiB
Java
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
//ProjectEuler/Java/Problem11.java
//Matthew Ellison
// Created: 03-03-19
//Modified: 03-28-19
//What is the greatest product of four adjacent numbers in the same direction (up, down, left, right, or diagonally) in the 20×20 grid?
/*
08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48
*/
//Unless otherwise listed all non-standard includes are my own creation and available from https://bibucket.org/Mattrixwv/JavaClasses
/*
Copyright (C) 2019 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/>.
*/
import mattrixwv.Stopwatch;
import mattrixwv.Algorithms;
import java.util.ArrayList;
public class Problem11{
//This is the grid of numbers that we will be working with
private static final Integer[][] grid = {{8, 02, 22, 97, 38, 15, 00, 40, 00, 75, 04, 05, 07, 78, 52, 12, 50, 77, 91, 8},
{49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48, 04, 56, 62, 00},
{81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30, 03, 49, 13, 36, 65},
{52, 70, 95, 23, 04, 60, 11, 42, 69, 24, 68, 56, 01, 32, 56, 71, 37, 02, 36, 91},
{22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80},
{24, 47, 32, 60, 99, 03, 45, 02, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50},
{32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70},
{67, 26, 20, 68, 02, 62, 12, 20, 95, 63, 94, 39, 63, 8, 40, 91, 66, 49, 94, 21},
{24, 55, 58, 05, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72},
{21, 36, 23, 9, 75, 00, 76, 44, 20, 45, 35, 14, 00, 61, 33, 97, 34, 31, 33, 95},
{78, 17, 53, 28, 22, 75, 31, 67, 15, 94, 03, 80, 04, 62, 16, 14, 9, 53, 56, 92},
{16, 39, 05, 42, 96, 35, 31, 47, 55, 58, 88, 24, 00, 17, 54, 24, 36, 29, 85, 57},
{86, 56, 00, 48, 35, 71, 89, 07, 05, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58},
{19, 80, 81, 68, 05, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77, 04, 89, 55, 40},
{04, 52, 8, 83, 97, 35, 99, 16, 07, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66},
{88, 36, 68, 87, 57, 62, 20, 72, 03, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69},
{04, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18, 8, 46, 29, 32, 40, 62, 76, 36},
{20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74, 04, 36, 16},
{20, 73, 35, 29, 78, 31, 90, 01, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57, 05, 54},
{01, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52, 01, 89, 19, 67, 48}};;
public static void main(String[] argv){
Stopwatch timer = new Stopwatch(); //Allows the program to the timed
ArrayList<Integer> greatestProduct = new ArrayList<Integer>(); //Holds the largest product we have found so far
ArrayList<Integer> currentProduct = new ArrayList<Integer>(); //Holds the numbers we are currently working on
//Make sure all elements have at least 4 elements
for(int cnt = 0;cnt < 4;++cnt){
greatestProduct.add(0);
currentProduct.add(0);
}
//Start the timer
timer.start();
//Loop through every row and column
for(Integer row = 0;row < 20;++row){
for(Integer col = 0;col < grid[row].length;++col){
//Directional booleans to show whether you can move a certain direction
Boolean left = false;
Boolean right = false;
Boolean down = false;
//Check which direction you will be able to move
if((col - 3) >= 1){
left = true;
}
if((col + 3) < grid[row].length){
right = true;
}
if((row + 3) < 20){
down = true;
}
//Check the direction you are able to go
//Right
if(right){
//Fill the product
currentProduct.set(0, grid[row][col]);
currentProduct.set(1, grid[row][col + 1]);
currentProduct.set(2, grid[row][col + 2]);
currentProduct.set(3, grid[row][col + 3]);
//If the current number's product is greater than the greatest product replace it
if(Algorithms.getProd(currentProduct) > Algorithms.getProd(greatestProduct)){
greatestProduct.set(0, currentProduct.get(0));
greatestProduct.set(1, currentProduct.get(1));
greatestProduct.set(2, currentProduct.get(2));
greatestProduct.set(3, currentProduct.get(3));
}
}
//Down
if(down){
//Fill the product
currentProduct.set(0, grid[row][col]);
currentProduct.set(1, grid[row + 1][col]);
currentProduct.set(2, grid[row + 2][col]);
currentProduct.set(3, grid[row + 3][col]);
//If the current number's product is greater than the greatest product replace it
if(Algorithms.getProd(currentProduct) > Algorithms.getProd(greatestProduct)){
greatestProduct.set(0, currentProduct.get(0));
greatestProduct.set(1, currentProduct.get(1));
greatestProduct.set(2, currentProduct.get(2));
greatestProduct.set(3, currentProduct.get(3));
}
}
//LeftDown
if(left && down){
//Fill the product
currentProduct.set(0, grid[row][col]);
currentProduct.set(1, grid[row + 1][col - 1]);
currentProduct.set(2, grid[row + 2][col - 2]);
currentProduct.set(3, grid[row + 3][col - 3]);
//If the current number's product is greater than the greatest product replace it
if(Algorithms.getProd(currentProduct) > Algorithms.getProd(greatestProduct)){
greatestProduct.set(0, currentProduct.get(0));
greatestProduct.set(1, currentProduct.get(1));
greatestProduct.set(2, currentProduct.get(2));
greatestProduct.set(3, currentProduct.get(3));
}
}
//RightDown
if(right && down){
//Fill the product
currentProduct.set(0, grid[row][col]);
currentProduct.set(1, grid[row + 1][col + 1]);
currentProduct.set(2, grid[row + 2][col + 2]);
currentProduct.set(3, grid[row + 3][col + 3]);
//If the current number's product is greater than the greatest product replace it
if(Algorithms.getProd(currentProduct) > Algorithms.getProd(greatestProduct)){
greatestProduct.set(0, currentProduct.get(0));
greatestProduct.set(1, currentProduct.get(1));
greatestProduct.set(2, currentProduct.get(2));
greatestProduct.set(3, currentProduct.get(3));
}
}
}
}
//Stop the timer
timer.stop();
//Print the resutls
System.out.printf("The greatest product of 4 numbers in a line is %d\n", Algorithms.getProd(greatestProduct));
System.out.println("The numbers are " + greatestProduct.toString());
System.out.println("It took " + timer.getStr() + " to run this algorithm");
}
}
/* Results:
The greatest product of 4 numbers in a line is 70600674
The numbers are [89, 94, 97, 87]
It took 2.442 milliseconds to run this algorithm
*/