class Board {
  let grid : [[Int]] = [
      [5, 3, 4,   6, 7, 8,   9, 1, 2],
      [6, 7, 2,   1, 9, 5,   3, 4, 8],
      [1, 9, 8,   3, 4, 2,   5, 6, 7],

      [8, 5, 9,   7, 6, 1,   4, 2, 3],
      [4, 2, 6,   8, 5, 3,   7, 9, 1],
      [7, 1, 3,   9, 2, 4,   8, 5, 6],

      [9, 6, 1,   5, 3, 7,   2, 8, 4],
      [2, 8, 7,   4, 1, 9,   6, 3, 5],
      [3, 4, 5,   2, 8, 6,   1, 7, 9],
  ]

  // (0,0) (0,1) (0,2)
  // (1,0) (1,1) (1,2)
  // (2,0) (2,1) (2,2)

  func validateArray(_ array: [Int]) -> Bool {
    var set = Set(array)
    return set.count == 9
  }

  func validateGridAt(_ row: Int, _ col: Int) -> Bool {
    for i in 0...2 {
      for j in 0...2 {
        set.insert(grid[i + row][j + col])
      }
    }
    if set.count != 9 {
      return false
    }
  }

  func validate() -> Bool {
    for i in 0..<9 {

      // if !validateArray(grid[i]) {
      //   return false
      // }

      var set = Set<Int>()
      for j in 0..<9 {
        set.insert(grid[i][j])
      }
      if set.count != 9 {
        return false
      }
    }

    for j in 0..<9 {
      var set = Set<Int>()
      for i in 0..<9 {
        set.insert(grid[i][j])
      }
      if set.count != 9 {
        return false
      }
    }

    // 0,0,3,3,6,6
    // for i in stride(from: 0, to: 9, by: 3) {

    for k in [0, 3, 6] {
      for l in 0..<2 {
        if !validateGridAt(k, l) {
          return false
        }

      var set = Set<Int>()
      for i in 0...2 {
        for j in 0...2 {
          set.insert(grid[i + (l * 3)][j + (k * 3)])
        }
      }
      if set.count != 9 {
        return false
      }
    }

    for k in 0..<2 {
      var set = Set<Int>()
      for i in 0...2 {
        for j in 0...2 {
          set.insert(grid[i + (k * 3)][j])
        }
      }
      if set.count != 9 {
        return false
      }
    }

    return true
  }
}

// for all i  for 0 a[0..j-1]
// add them all to a set the count should be 9
// i (0..2) , j (0,2)

let b = Board()
print(b.validate())