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ProjectEulerCS/ProjectEulerCS/Problems/Problem11.cs

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//ProjectEuler/ProjectEulerCS/src/Problems/Problem11.cs
//Matthew Ellison
// Created: 08-24-20
//Modified: 08-24-20
//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/CSClasses
/*
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
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/>.
*/
using System.Collections.Generic;
using System.Linq;
namespace ProjectEulerCS.Problems{
public class Problem11 : Problem{
//Variables
//Static variables
//This is the grid of numbers that we will be working with
private static readonly int[,] 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}};
//Instance variables
private List<int> greatestProduct; //Holds the largest product we have found so far
public List<int> Numbers{
get{
if(!solved){
throw new Unsolved();
}
return greatestProduct;
}
}
public int Product{
get{
if(!solved){
throw new Unsolved();
}
return mee.Algorithms.GetProd(greatestProduct);
}
}
//Functions
//Constructor
public Problem11() : base("What is the greatest product of four adjacent numbers in the same direction (up, down, left, right, or diagonally) in the 20×20 grid?"){
greatestProduct = new List<int>(){0, 0, 0, 0};
}
//Operational functions
//Solve the problem
public override void Solve(){
//If the problem has already been solved do nothing and end the function
if(solved){
return;
}
//Holds the numbers we are currently working on
List<int> currentProduct = new List<int>() {0, 0, 0, 0};
//Start the timer
_timer.Start();
//Loop through every row and column
for(int row = 0;row < grid.GetLength(0);++row){
for(int col = 0;col < grid.GetLength(1);++col){
//DIrectional booleans to show whether you can move a certain direction
bool left = false;
bool right = false;
bool down = false;
//Check which direction you will be able to move
if((col - 3) > 1){
left = true;
}
if((col + 3) < grid.GetLength(1)){
right = true;
}
if((row + 3) < 20){
down = true;
}
//Check the direction you are able to go
//Right
if(right){
//Fill the product
currentProduct[0] = grid[row, col];
currentProduct[1] = grid[row, col + 1];
currentProduct[2] = grid[row, col + 2];
currentProduct[3] = grid[row, col + 3];
//If the current number's product is greater than the greatest product replace it
if(mee.Algorithms.GetProd(currentProduct) > mee.Algorithms.GetProd(greatestProduct)){
greatestProduct = currentProduct.ToList();
}
}
//Down
if(down){
//Fill the product
currentProduct[0] = grid[row, col];
currentProduct[1] = grid[row + 1, col];
currentProduct[2] = grid[row + 2, col];
currentProduct[3] = grid[row + 3, col];
//If the current number's product is greater than the greatest product replace it
if(mee.Algorithms.GetProd(currentProduct) > mee.Algorithms.GetProd(greatestProduct)){
greatestProduct = currentProduct.ToList();
}
}
//Left & Down
if(left && down){
//Fill the product
currentProduct[0] = grid[row, col];
currentProduct[1] = grid[row + 1, col - 1];
currentProduct[2] = grid[row + 2, col - 2];
currentProduct[3] = grid[row + 3, col - 3];
//If the current number's product is greater than the greatest product replace it
if(mee.Algorithms.GetProd(currentProduct) > mee.Algorithms.GetProd(greatestProduct)){
greatestProduct = currentProduct.ToList();
}
}
//Right & Down
if(right && down){
//Fill the product
currentProduct[0] = grid[row, col];
currentProduct[1] = grid[row + 1, col + 1];
currentProduct[2] = grid[row + 2, col + 2];
currentProduct[3] = grid[row + 3, col + 3];
//If the current number's product is greater than the greatest product replace it
if(mee.Algorithms.GetProd(currentProduct) > mee.Algorithms.GetProd(greatestProduct)){
greatestProduct = currentProduct.ToList();
}
}
}
}
//Stop the timer
_timer.Stop();
//Throw a flag to show the problem is solved
solved = true;
//Save the results
_result = "The greatest product of 4 numbers in a line is " + mee.Algorithms.GetProd(greatestProduct) + "\n" +
"The numbers are [" + string.Join(", ", greatestProduct) + "]";
}
//Reset the problem so it can be run again
public override void Reset(){
base.Reset();
greatestProduct = new List<int>(){0, 0, 0, 0};
}
}
}
/* Results:
The greatest product of 4 numbers in a line is 70600674
The numbers are [89, 94, 97, 87]
It took an average of 46.957 microseconds to run this problem through 100 iterations
*/