811. Subdomain Visit Count.md

811. Subdomain Visit Count (Medium)

Python Tips:

• '.'.join([])
• re.split() or split()
• Counter() from collections
• defaultdict() from collections

Algorithm

• split the count first
• split domain, add all levels to a dict
• if exist, add counnt, else, add domain and count.

import re
class Solution:
    def subdomainVisits(self, cpdomains: List[str]) -> List[str]:
        
        # print(re.split(".| ", cpdomains[0]))
        # print(re.findall(r"[\w']+", cpdomains[0]))
        # print(re.split('\W', '900 google.ma-il.com'))
        # print(cpdomains[0].replace('.',' ').split())
        # domain_dict = {}
        domain_dict = defaultdict(lambda: 0)
        ans = []
        for one_domain in cpdomains:
            count, domain = one_domain.split()
            domain = domain.split('.')
            for i in range(len(domain)):
                sub_domain = '.'.join(domain[i:])
                domain_dict[sub_domain] += int(count)
        # for sub_domain, value in domain_dict.items():
        #     ans.append(str(value) + " " + sub_domain)
        # ans = ["{} {}".format(count, domain) for domain, count in domain_dict.items()]
        ans = [f"{count} {domain}" for domain, count in domain_dict.items()]
        return ans