对于n个变量,存在2 ^(2 ^ n)个不同的布尔函数。例如,如果n = 2,则存在16个可能的布尔函数,这些布尔函数可以乘积形式或乘积形式写入。可能函数的数量呈n指数增长。
我正在寻找一种算法,可以为n个变量生成所有这些可能的布尔规则。我曾尝试在各个地方进行搜索,但直到现在都找不到合适的东西。大多数算法与将布尔函数简化或减少为标准形式有关。
我知道即使对于n = 8或9,规则数量也变得太大,但是有人可以帮助我解决相关算法吗?
n个 变量的布尔函数具有 2 ^ n个 可能的输入。可以通过打印范围内的值的二进制表示形式来枚举这些值0 <= x < 2^n。
0 <= x < 2^n
对于这些可能的输入中的每个输入,布尔函数可以输出 0 或 1 。列举所有可能性(即每个可能的真值表)。列出range中的二进制值0 <= x < 2^(2^n)。
0 <= x < 2^(2^n)
这是Python中的算法:
from __future__ import print_function from itertools import product # forms cartesian products n = 3 # number of variables print('All possible truth tables for n =', n) inputs = list(product([0, 1], repeat=n)) for output in product([0, 1], repeat=len(inputs)): print() print('Truth table') print('-----------') for row, result in zip(inputs, output): print(row, '-->', result)
输出看起来像这样:
All possible truth tables for n = 3 Truth table ----------- (0, 0, 0) --> 0 (0, 0, 1) --> 0 (0, 1, 0) --> 0 (0, 1, 1) --> 0 (1, 0, 0) --> 0 (1, 0, 1) --> 0 (1, 1, 0) --> 0 (1, 1, 1) --> 0 Truth table ----------- (0, 0, 0) --> 0 (0, 0, 1) --> 0 (0, 1, 0) --> 0 (0, 1, 1) --> 0 (1, 0, 0) --> 0 (1, 0, 1) --> 0 (1, 1, 0) --> 0 (1, 1, 1) --> 1 Truth table ----------- (0, 0, 0) --> 0 (0, 0, 1) --> 0 (0, 1, 0) --> 0 (0, 1, 1) --> 0 (1, 0, 0) --> 0 (1, 0, 1) --> 0 (1, 1, 0) --> 1 (1, 1, 1) --> 0 Truth table ----------- (0, 0, 0) --> 0 (0, 0, 1) --> 0 (0, 1, 0) --> 0 (0, 1, 1) --> 0 (1, 0, 0) --> 0 (1, 0, 1) --> 0 (1, 1, 0) --> 1 (1, 1, 1) --> 1 ... and so on
如果要以代数形式而不是真值表形式输出,则算法是相同的:
from __future__ import print_function from itertools import product # forms cartesian products n = 3 # number of variables variables = 'abcdefghijklmnopqrstuvwxyz'[:n] pairs = [('~'+var, var) for var in variables] print('All possible algebraic expressions for n =', n) inputs = list(product(*pairs)) for i, outputs in enumerate(product([0, 1], repeat=len(inputs))): terms = [''.join(row) for row, output in zip(inputs, outputs) if output] if not terms: terms = ['False'] print('Function %d:' % i, ' or '.join(terms))
All possible algebraic expressions for n = 3 Function 0: False Function 1: abc Function 2: ab~c Function 3: ab~c or abc Function 4: a~bc Function 5: a~bc or abc Function 6: a~bc or ab~c Function 7: a~bc or ab~c or abc Function 8: a~b~c Function 9: a~b~c or abc Function 10: a~b~c or ab~c Function 11: a~b~c or ab~c or abc Function 12: a~b~c or a~bc Function 13: a~b~c or a~bc or abc Function 14: a~b~c or a~bc or ab~c Function 15: a~b~c or a~bc or ab~c or abc Function 16: ~abc Function 17: ~abc or abc Function 18: ~abc or ab~c Function 19: ~abc or ab~c or abc Function 20: ~abc or a~bc Function 21: ~abc or a~bc or abc Function 22: ~abc or a~bc or ab~c Function 23: ~abc or a~bc or ab~c or abc Function 24: ~abc or a~b~c Function 25: ~abc or a~b~c or abc Function 26: ~abc or a~b~c or ab~c Function 27: ~abc or a~b~c or ab~c or abc Function 28: ~abc or a~b~c or a~bc Function 29: ~abc or a~b~c or a~bc or abc Function 30: ~abc or a~b~c or a~bc or ab~c Function 31: ~abc or a~b~c or a~bc or ab~c or abc Function 32: ~ab~c Function 33: ~ab~c or abc ... and so on