string_permutation.py

string_permutation.py

class StringPermutation:

    def __init__(self):
        self.dict = {}
        self.chars = []
        self.count = []
        self.result = []

    def run(self, string):
        for char in string:
            self.result.append(char)
            if char in self.dict.keys():
                self.dict[char] += 1
            else:
                self.dict[char] = 1

        for i, entry in enumerate(self.dict.items()):
            self.chars.append(entry[0])
            self.count.append(entry[1])

        self.permute(0)

    def permute(self, level):
        if level == len(self.dict):
            print(''.join(self.result))
            return

        for i in range(len(self.dict)):

            if self.count[i] == 0:
                continue

            self.result[level] = self.chars[i]
            self.count[i] -= 1
            self.permute(level + 1)
            self.count[i] += 1


def main():
    string = "AABC"
    StringPermutation().run(string)

if __name__ == "__main__":
    main()