Sudoku: Difference between revisions

Line 1,835:

namespace Sudoku {

static class Program {

private static bool Unique(IEnumerable<int> values) => values.Distinct().Count() == values.Count();

private static bool Unique(this IEnumerable<int> values) => values.Distinct().Count() == values.Count();

private static bool IsUnequal(IEnumerable<int> values) => ~~Unique(~~values.Where(c => c != 0));

private static bool IsUnequal(this IEnumerable<int> values) => values.Where(c => c != 0).Unique();

private static int RowCol(int rc) => rc <= 2 ? 0 : rc <= 5 ? 3 : 6;

Line 1,844:

select grid[r][c];

private static bool Constraints(int[][] grid, int row, int col) =>

private static bool Constraints(this int[][] grid, int row, int col) =>

~~IsUnequal(~~Range(0, 9).Select(c => grid[row][c])) &&

Range(0, 9).Select(c => grid[row][c]).IsUnequal() &&

~~IsUnequal(~~Range(0, 9).Select(r => grid[r][col])) &&

Range(0, 9).Select(r => grid[r][col]).IsUnequal() &&

~~IsUnequal(~~GetBox(grid, row, col));

GetBox(grid, row, col).IsUnequal();

private static (int, int) NextEmptyCell(int[][] grid, int r, int c) {

private static (int, int) NextEmptyCell(this int[][] grid, int r, int c) {

while (r < 9 && grid[r][c] != 0) {

c = ++c % 9;

Line 1,857:

}

private static (bool, int[][]) Solve(int[][] grid, int row, int col) {

private static (bool, int[][]) Solve(this int[][] grid, int row, int col) {

var (r, c) = NextEmptyCell(~~grid,~~ row, col);

var (r, c) = grid.NextEmptyCell(row, col);

if (r == 9) //success

Line 1,865:

for (var i = 1; i <= 9; i++) {

grid[r][c] = i;

if (!Constraints(~~grid,~~ r, c))

if (!grid.Constraints(r, c))

continue;

var (success, g) = Solve(~~grid,~~ r, c);

var (success, g) = grid.Solve(r, c);

if (!success)

continue;

Line 1,893:

.ToArray();

var (success, result) = Solve(~~input,~~ 0, 0);

var (success, result) = input.Solve(0, 0);

if (success)

Line 1,907:

}

}</lang>

</lang>

Output

<pre>975342861