Initial commit

go.mod

@@ -0,0 +1,3 @@
+module "github.com/djpianalto/sudokuSolver"
+
+go 1.14

solver.go

@@ -0,0 +1,62 @@
+package sudokuSolver
+
+import (
+	"context"
+	"math"
+)
+
+func isValid(grid [][]int, x, y, i int) bool {
+	for n := 0; n < 9; n++ {
+		if grid[y][n] == i || grid[n][x] == i{
+			return false
+		}
+	}
+	topX, topY := int(3 * (math.Floor(float64(x/3)))), int(3 * (math.Floor(float64(y/3))))
+	for x := topX; x < topX + 3; x++ {
+		for y := topY; y < topY + 3; y++ {
+			if grid[y][x] == i {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+func findNextEmptyCell(grid [][]int) (int,int) {
+	for y := 0; y < 9; y++ {
+		for x := 0; x < 9; x++ {
+			if grid[y][x] == 0 {
+				return x, y
+			}
+		}
+	}
+	return -1, -1
+}
+
+func SolveSudoku(grid [][]int, x, y int, ctx context.Context) bool {
+	select {
+	case <-ctx.Done():
+		return false
+	default:
+	}
+	x, y = findNextEmptyCell(grid)
+	if x == -1 && y == -1 {
+		return true
+	}
+	for i := 1; i <= 9; i++ {
+		if isValid(grid, x, y, i) {
+			grid[y][x] = i
+			if SolveSudoku(grid, x, y, ctx) {
+				return true
+			}
+			select {
+			case <-ctx.Done():
+				return false
+			default:
+			}
+			grid[y][x] = 0
+		}
+	//time.Sleep(100000000)
+	}
+	return false
+}