from utils import *
from math import *

def grid_values(grid):
    """Convert grid string into {<box>: <value>} dict with '123456789' value for empties.

    Args:
        grid: Sudoku grid in string form, 81 characters long
    Returns:
        Sudoku grid in dictionary form:
        - keys: Box labels, e.g. 'A1'
        - values: Value in corresponding box, e.g. '8', or '123456789' if it is empty.
    """
    assert len(grid) == 81, "Input must be 81 characters"
    
    result = {}
    rowNum = 0

    for i in range(0, len(grid)):
        if i > 0 and i % len(cols) == 0:
            rowNum = rowNum + 1

        rowName = rows[rowNum]
        colName = cols[i % len(cols)]
        
        key = rowName + colName

        result[key] = grid[i] if grid[i] != '.' else cols

    return result