64 lines
1.3 KiB
Swift
64 lines
1.3 KiB
Swift
func solving(board: [[Int]]) -> [[Int]] {
|
|
var board = board
|
|
var isSolved = false
|
|
while !isSolved {
|
|
for x in 0 ..< 9 {
|
|
for y in 0 ..< 9 {
|
|
if board[x][y] == 0 {
|
|
let known = Set(board.map { $0[y] } + board[x] + subgrid(board, pos: (x, y)))
|
|
let possible = Set(Array(1...9)).subtracting(known)
|
|
if possible.count == 1 {
|
|
board[x][y] = possible.first!
|
|
}
|
|
}
|
|
}
|
|
isSolved = 45 == board[x].reduce(0, +)
|
|
}
|
|
}
|
|
return board
|
|
}
|
|
|
|
func subgrid(_ board: [[Int]], pos: (Int, Int)) -> [Int] {
|
|
var r = [Int]()
|
|
var (x, y) = pos
|
|
x = x / 3 * 3
|
|
y = y / 3 * 3
|
|
for i in x ..< x + 3 {
|
|
for j in y ..< y + 3 {
|
|
r.append(board[i][j])
|
|
}
|
|
}
|
|
return r
|
|
}
|
|
|
|
func print(_ board: [[Int]]) {
|
|
for i in board.indices {
|
|
if i % 9 == 0 {
|
|
print(" -------------------")
|
|
}
|
|
for j in board.indices {
|
|
if j % board.count == 0 {
|
|
print("| ", terminator: "")
|
|
}
|
|
let digit = board[i][j]
|
|
print(digit != 0 ? digit : " ", terminator: "")
|
|
print(" ", terminator: "")
|
|
}
|
|
print("|")
|
|
}
|
|
print(" -------------------")
|
|
}
|
|
|
|
let puzzle = [
|
|
[0,2,0,4,5,0,7,0,9],
|
|
[0,0,0,1,0,9,0,3,0],
|
|
[0,0,8,0,0,0,1,0,4],
|
|
[0,4,0,0,6,1,0,7,0],
|
|
[5,0,6,0,3,0,0,1,0],
|
|
[0,3,0,0,0,2,0,9,0],
|
|
[3,0,4,0,7,5,0,6,8],
|
|
[0,9,0,0,1,0,3,0,7],
|
|
[0,0,2,0,0,3,0,0,1]
|
|
]
|
|
|
|
print(solving(board: puzzle))
|