Practice>Python>Regex and Parsing>Validating Credit Card Numbers

hackerrank.com

Validating Credit Card Numbers

Problem Link : https://www.hackerrank.com/challenges/validating-credit-card-number/problem

Difficulty : Medium

 

Tip

• It's a bit difficult to solve only using regular expression
• Especially, 'NOT have  or more consecutive repeated digits'
• More over, in test case 6, '-------' is given as a part of input, it should be filtered, also
• Check condition 1~4 by using regular expression
• Check condtion 5~6 by other code

 

Solution

import re N = int(input()) p = re.compile(r'([456]{1}\d{3})(\-*\d{4})+') def same4(s): for i in range(len(s)-(4-1)): if s[i] == s[i+1]: if s[i] == s[i+2]: if s[i] == s[i+3]: return True return False for _ in range(N): s = input() #print(s) if p.match(s): #print(p.match(s)[0]) s4 = s if s4.count('-') > 3: print('Invalid') continue s4 = s4.replace('-', '') s4 = s4.replace(' ', '') if same4(s4) or len(s4) != 16: print('Invalid') continue print('Valid') else: print('Invalid')