R/grid_gen_cplt.R

In RSDK: Sudoku with R

#' grid_gen_cplt()
#'
#' This function generates a complete sudoku grid randomly
#'
#' @return A complete sudoku grid
#'
#' @examples Grid_complete = grid_gen_cplt()
#' @export
grid_gen_cplt <- function() {
  A <- matrix(rep(NA, 81), 9, 9)
  A[1, ] <- sample(1:9)
  t <- 1:3
  for (i in 1:2) {
    # 1:3 x 1:9
    A[i + 1, ] <- perm_mat(A[i, ], 3)
  }
  for (k in seq(0, 8, 3)) {
    # 4:9 x 1:9
    for (i in 1:2) {
      A[t + 3 * i, t + k] <- perm_mat(A[t, t + k], c(0, i))
    }
  }
  for (k in seq(0, 8, 3)) {
    A[t + k, ] <- A[sample(t + k), ]
  }
  for (j in seq(0, 8, 3)) {
    A[, t + j] <- A[, sample(t + j)]
  }
  return(A)
}