Usage

Run the program

On the command line, type the following, where [filename] is the name of your text file that contains a table of numbers. (See below for examples of tables.)

$ python3 largest_prod_grid.py [filename]

Run the program with debugging print statements

To show print statements designed to help debug the program, open the program in an editor and set the verbose flag to True.

verbose = True

Examples of number tables

The file should contain a square table of integers separated by spaces. Here are two examples of tables (these are also in the repo).

A 20 x 20 table:

02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48

A 5 x 5 table. Note that one-digit numbers don’t need to have leading zeroes:

2 3 4 5
7 8 9 10
12 13 14 15
17 18 19 20
22 23 24 25

Example output

When the program runs successfully, the output looks like this:

The largest product of four adjacent numbers in the table is 70600674.