Data commit

Task/Sudoku/11l/sudoku.11l

@@ -0,0 +1,72 @@
+T Sudoku
+   solved = 0B
+   grid = [0] * 81
+
+   F (rows)
+      assert(rows.len == 9 & all(rows.map(row -> row.len == 9)), ‘Grid must be 9 x 9’)
+      L(i) 9
+         L(j) 9
+            .grid[9 * i + j] = Int(rows[i][j])
+
+   F solve()
+      print("Starting grid:\n\n"(.))
+      .placeNumber(0)
+      print(I .solved {"Solution:\n\n"(.)} E ‘Unsolvable!’)
+
+   F placeNumber(pos)
+      I .solved
+         R
+      I pos == 81
+         .solved = 1B
+         R
+
+      I .grid[pos] > 0
+         .placeNumber(pos + 1)
+         R
+
+      L(n) 1..9
+         I .checkValidity(n, pos % 9, pos I/ 9)
+            .grid[pos] = n
+            .placeNumber(pos + 1)
+            I .solved
+               R
+            .grid[pos] = 0
+
+   F checkValidity(v, x, y)
+      L(i) 9
+         I .grid[y * 9 + i] == v |
+           .grid[i * 9 + x] == v
+            R 0B
+
+      V startX = (x I/ 3) * 3
+      V startY = (y I/ 3) * 3
+      L(i) startY .< startY + 3
+         L(j) startX .< startX + 3
+            I .grid[i * 9 + j] == v
+               R 0B
+
+      R 1B
+
+   F String()
+      V s = ‘’
+      L(i) 9
+         L(j) 9
+            s ‘’= .grid[i * 9 + j]‘ ’
+            I j C (2, 5)
+               s ‘’= ‘| ’
+         s ‘’= "\n"
+         I i C (2, 5)
+            s ‘’= "------+-------+------\n"
+      R s
+
+V rows = [‘850002400’,
+          ‘720000009’,
+          ‘004000000’,
+          ‘000107002’,
+          ‘305000900’,
+          ‘040000000’,
+          ‘000080070’,
+          ‘017000000’,
+          ‘000036040’]
+
+Sudoku(rows).solve()