Algorithm
Problem Name: Python -
In this HackerRank Functions in PYTHON problem solution,
group()
A group() expression returns one or more subgroups of the match.
Code
>>> import re
>>> m = re.match(r'(\w+)@(\w+)\.(\w+)','username@hackerrank.com')
>>> m.group(0) # The entire match
'username@hackerrank.com'
>>> m.group(1) # The first parenthesized subgroup.
'username'
>>> m.group(2) # The second parenthesized subgroup.
'hackerrank'
>>> m.group(3) # The third parenthesized subgroup.
'com'
>>> m.group(1,2,3) # Multiple arguments give us a tuple.
('username', 'hackerrank', 'com')
groups()
A groups() expression returns a tuple containing all the subgroups of the match.
Code
>>> import re
>>> m = re.match(r'(\w+)@(\w+)\.(\w+)','username@hackerrank.com')
>>> m.groups()
('username', 'hackerrank', 'com')
groupdict()
A groupdict() expression returns a dictionary containing all the named subgroups of the match, keyed by the subgroup name.
Code
>>> m = re.match(r'(?P<user>\w+)@(?P<website>\w+)\.(?P<extension>\w+)','myname@hackerrank.com')
>>> m.groupdict()
{'website': 'hackerrank', 'user': 'myname', 'extension': 'com'}
Task
You are given a string S.
Your task is to find the first occurrence of an alphanumeric character in S (read from left to right) that has consecutive repetitions.
Input Format
A single line of input containing the string S.
Constraints
0 < len(S) < 100
Output Format
Print the first occurrence of the repeating character. If there are no repeating characters, print -1.
Sample Input
..12345678910111213141516171820212223
Sample Output
1
Explanation
.. is the first repeating character, but it is not alphanumeric.
1 is the first (from left to right) alphanumeric repeating character of the string in the substring 111
Code Examples
#1 Code Example with Python Programming
Code -
Python Programming
import re
m = re.search(r"([a-z0-9])\1{1,}", input())
if m:
print(m.group(1))
else:
print(-1)