project euler 11, C#, C#

Language: Layout:

//Title of this code
//Rextester.Program.Main is the entry point for your code. Don't change it.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            string s_grid = Console.In.ReadToEnd();
            string[] n = s_grid.Split(" \n".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
            int size = 20;
            int window = 4;
            List<List<int>> grid = new List<List<int>>();
            int counter = 0;
            foreach(var s in n)
            {
                if(counter==size)
                    break;
                var row = new List<int>();
                for(int i=0; i<size; i++)
                {
                    row.Add(Convert.ToInt32(n[counter*size+i]));
                }                
                
                grid.Add(row);
                counter++;
            }
            
            int max_hor = Max(grid, window);
            int max_ver = Max(Transpose(grid), window);
            int max_diag = Max(RowsFromDiagonals(grid), window);
            Console.WriteLine(new List<int>(){max_hor, max_ver, max_diag}.Max());
        }
        
        public static int Max(List<List<int>> grid, int window)
        {
            int max = 0;
            foreach(var row in grid)
            {
                for(int i=0; i<row.Count(); i++)
                {
                    int product = 1;
                    for(int j=i; j<i+window; j++)
                    {
                        if(row.Count() <= j)
                            break;
                        product *= row[j];
                        
                        if(product > max)
                            max = product;
                    }
                }
            }
            return max;
        }
        
        public static List<List<int>> Transpose(List<List<int>> grid)
        {
            var res = new List<List<int>>();
            for(int column=0; column<grid.Count(); column++)
            {
                List<int> row_t = new List<int>();
                foreach(var row in grid)
                {
                    row_t.Add(row[column]);
                }
                res.Add(row_t);
            }
            return res;
        }
        
        public static List<List<int>> RowsFromDiagonals(List<List<int>> grid)
        {
            var res = new List<List<int>>();
            for(int i=0; i<grid[0].Count(); i++)
            {
                List<int> row = new List<int>();
                for(int j=0, k=i; ; j++, k++)
                {
                    if(grid.Count() <= j || grid.Count() <= k)
                        break;
                    row.Add(grid[j][k]);
                }
                res.Add(row);
            }
            
            var grid_t = Transpose(grid);
            for(int i=0; i<grid_t[0].Count(); i++)
            {
                List<int> row = new List<int>();
                for(int j=0, k=i; ; j++, k++)
                {
                    if(grid_t.Count() <= j || grid_t.Count() <= k)
                        break;
                    row.Add(grid_t[j][k]);
                }
                res.Add(row);
            }
            
            //the "other" diagonals
            for(int i=grid[0].Count()-1; i>=0; i--)
            {
                List<int> row = new List<int>();
                for(int j=0, k=i; ; j++, k--)
                {
                    if(grid.Count() <= j || k < 0)
                        break;
                    row.Add(grid[j][k]);
                }
                res.Add(row);
            }
         
            //...
            
            return res;
        }
        
        
        
        
        
        
        
        
        
        
        
        
        
    }
}

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

Show compiler warnings [ - ] Show input
Compilation time: 0.34 sec, absolute running time: 0.19 sec, cpu time: 0.14 sec, average memory usage: 18 Mb, average nr of threads: 4