aiSandbox/csp_solver.py

#!/usr/bin/env python3

from sudoku import Game

MAX_V = 9
class State:

    def __init__(self):
        resultboard = []
        for x in range(MAX_V):
            temprow = []
            for y in range(MAX_V):
                temprow.append(0)
            resultboard.append(temprow)
        self.resultboard = resultboard

        choicesboard = []
        # Populate the numbers vector with values from 1 to MAX_V

        # choicesboard is a bidimensional list with numbers for every element
        for x in range(MAX_V):
            row = []
            for y in range(MAX_V):
                numbers = set()
                for value in range(1,10):
                    numbers.add(value)
                row.append(numbers)
            choicesboard.append(row)
        self.choicesboard = choicesboard

def actions(state):
    actions = []
    for row in range(MAX_V):
        for col in range(MAX_V):
            #Value not yet assigned
            if state.resultboard[col][row] == 0:
                #Add possible move
                for num in state.choicesboard[col][row]:
                    move = {'col': col, 'row': row, 'num': num}
                    actions.append(move)
    return actions

def result(state,move):
    state.resultboard[move['col']][move['row']] = move['num']

def goalTest(state):
    incomplete = False
    for row in range(MAX_V):
        for col in range(MAX_V):
            if state.resultboard[col][row] == 0:
                imcomplete = True
    return incomplete

def eliminateIllValues(state):
    for row in range(MAX_V):
        for col in range(MAX_V):
            if state.resultboard[col][row] != 0:
                num = state.resultboard[col][row]
                # Eliminate duplicates numbers in a row
                for x in range(MAX_V):
                    state.choicesboard[x][row].remove(num)
                    # Eliminate duplicates numbers in a column
                for y in range(MAX_V):
                    state.choicesboard[col][y].remove(num)
                    # Eliminate duplicates in block (working only for 9x9 cells)
                #for y in range(MAX_V)
                #    choicesboard[col][y].del(state.resultboard[col][row])

if __name__ == "__main__":
    node = State()
    while not goalTest(node):
        move=actions(node).pop()
        result(node,move)
        eliminateIllValues(node)
    print('Result found!')