python實現並查表

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class UnionFindSet(object):    """並查表"""    def __init__(self, data_list):        """初始化兩個字典，一個儲存節點的父節點，另外一個儲存父節點的大小        初始化的時候，將節點的父節點設為自身，size設為1"""        self.father_dict = {}        self.size_dict = {}        for node in data_list:            self.father_dict[node] = node            self.size_dict[node] = 1    def find_head(self, node):        """使用遞迴的方式來尋找父節點        在尋找父節點的時候，順便把當前節點移動到父節點上面        這個操作算是一個最佳化        """        father = self.father_dict[node]        if(node != father):            father = self.find_head(father)        self.father_dict[node] = father        return father    def is_same_set(self, node_a, node_b):        """查看兩個節點是不是在一個集合裡面"""        return self.find_head(node_a) == self.find_head(node_b)    def union(self, node_a, node_b):        """將兩個集合合并在一起"""        if node_a is None or node_b is None:            return        a_head = self.find_head(node_a)        b_head = self.find_head(node_b)        if(a_head != b_head):            a_set_size = self.size_dict[a_head]            b_set_size = self.size_dict[b_head]            if(a_set_size >= b_set_size):                self.father_dict[b_head] = a_head                self.size_dict[a_head] = a_set_size + b_set_size            else:                self.father_dict[a_head] = b_head                self.size_dict[b_head] = a_set_size + b_set_sizeif __name__ == ‘__main__‘:    a = [1,2,3,4,5]    union_find_set = UnionFindSet(a)    union_find_set.union(1,2)    union_find_set.union(3,5)    union_find_set.union(3,1)    print(union_find_set.is_same_set(2,5))  # True

 

python實現並查表