-
-
Save CalfordMath/0aaa29d5dbaa50a85211253f6febf03f to your computer and use it in GitHub Desktop.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| //ref: https://codereview.stackexchange.com/q/199771 | |
| //CalfordMath edit notes: | |
| //I placed the "test" lambda inside of "solver" to acheive a single Lambda function (nested recursive). | |
| //I'm not sure this optimizes anything computationally, and perhaps it makes the code less easy to follow, | |
| //but I find it satisfying to have everything wrapped in a single function :) | |
| solver = LAMBDA(grid, | |
| LET( | |
| numbers, SEQUENCE(9), | |
| numgrid, SEQUENCE(9, 9, 0), | |
| pos, XMATCH(0, TOCOL(grid * 1)) - 1, | |
| IF( | |
| ISNA(pos), | |
| grid, | |
| LET( | |
| i, INT(pos / 9), | |
| j, MOD(pos, 9), | |
| row, INDEX(grid, i + 1, ), | |
| col, INDEX(grid, , j + 1), | |
| sqr, INDEX(grid, FLOOR(i, 3) + {1; 2; 3}, FLOOR(j, 3) + {1, 2, 3}), | |
| values, UNIQUE(VSTACK(numbers, col, TOCOL(row), TOCOL(sqr)), , 1), | |
| test, LAMBDA(test, values, function, | |
| IF(COUNT(values), | |
| IFNA(function(@values), | |
| test(test, DROP(values, 1), function) | |
| ), | |
| NA() | |
| ) | |
| ), | |
| test(test, values, LAMBDA(value, solver(IF(numgrid = pos, value, grid)))) | |
| ) | |
| ) | |
| ) | |
| ); | |
| //example: | |
| //=solver({ | |
| //0,0,0,0,0,0,0,9,0; | |
| //0,9,7,0,0,0,4,0,0; | |
| //0,0,8,0,6,0,0,7,0; | |
| //0,0,0,9,8,7,0,0,0; | |
| //0,0,0,0,0,4,0,0,1; | |
| //0,0,0,0,0,6,0,2,4; | |
| //2,0,0,0,0,0,5,0,3; | |
| //0,4,0,0,5,0,0,0,0; | |
| //6,0,0,8,0,0,0,0,0}) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment