def permute(arr):

dict = {}

for i in arr:

if i in dict.keys():

dict[i] = dict[i] + 1

else:

dict[i] = 1

keys = sorted(dict)

str = []

count = []

start=0

for key in keys:

str.append(key)

count.append(dict[key])

result = [0]*len(arr)

print(str, count, result, start)

permutation(str, count, result, start)

def permutation(str, count, result, start):

if start == len(result):

print(result)

return

for i in range(len(str)):

if count[i] == 0:

continue

result[start] = str[i]

count[i] -= 1

permutation(str, count, result, start + 1)

count[i] += 1

if __name__ == '__main__':

input = ['A', 'A', 'B','C']

permute(input)