99 lines
1.7 KiB
Go
99 lines
1.7 KiB
Go
package main
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import "fmt"
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var field = [9][9]int{
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{5, 3, 0, 0, 7, 0, 0, 0, 0},
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{6, 0, 0, 1, 9, 5, 0, 0, 0},
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{0, 9, 8, 0, 0, 0, 0, 6, 0},
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{8, 0, 0, 0, 6, 0, 0, 0, 3},
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{4, 0, 0, 8, 0, 3, 0, 0, 1},
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{7, 0, 0, 0, 2, 0, 0, 0, 6},
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{0, 6, 0, 0, 0, 0, 2, 8, 0},
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{0, 0, 0, 4, 1, 9, 0, 0, 5},
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{0, 0, 0, 0, 8, 0, 0, 7, 9},
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}
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func draw() {
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for _, row := range field {
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fmt.Println(row)
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}
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fmt.Println()
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}
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func canPut(x int, y int, value int) bool {
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return !alreadyInVertical(x, y, value) &&
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!alreadyInHorizontal(x, y, value) &&
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!alreadyInSquare(x, y, value)
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}
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func alreadyInVertical(x int, y int, value int) bool {
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for i := range [9]int{} {
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if field[i][x] == value {
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return true
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}
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}
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return false
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}
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func alreadyInHorizontal(x int, y int, value int) bool {
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for i := range [9]int{} {
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if field[y][i] == value {
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return true
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}
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}
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return false
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}
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func alreadyInSquare(x int, y int, value int) bool {
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sx, sy := int(x/3)*3, int(y/3)*3
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for dy := range [3]int{} {
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for dx := range [3]int{} {
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if field[sy+dy][sx+dx] == value {
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return true
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}
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}
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}
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return false
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}
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func next(x int, y int) (int, int) {
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nextX, nextY := (x+1)%9, y
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if nextX == 0 {
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nextY = y + 1
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}
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return nextX, nextY
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}
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func solve(x int, y int) bool {
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if y == 9 {
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return true
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}
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if field[y][x] != 0 {
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return solve(next(x, y))
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} else {
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for i := range [9]int{} {
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var v = i + 1
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if canPut(x, y, v) {
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field[y][x] = v
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if solve(next(x, y)) {
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return true
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}
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field[y][x] = 0
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}
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}
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return false
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}
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}
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func main() {
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fmt.Println("Grid to be completed:")
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draw()
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if solve(0, 0) {
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fmt.Println("I found a solution, see below")
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draw()
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} else {
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fmt.Println("I did not find a solution")
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}
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}
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