Python | Check if given string can be formed by concatenating string elements of list
Given a string ‘str’ and a list of string elements, write a Python program to check whether given string can be formed by concatenating the string elements of list or not.
Examples:
Input : str = 'python'
lst = ['co', 'de', 'py', 'ks', 'on']
Output : False
Input : str = 'geeks'
lst = ['for', 'ge', 'abc', 'ks', 'e', 'xyz']
Output : True
Approach #1 : Using itertools.permuations
We can use all the permutations of the given list and then perform join operation on them. If any join result is equal to the given string, return true, otherwise false.
# Python3 program to Check if given string can # be formed by concatenating string elements # of list from itertools import permutations def checkList(str, lst): for i in range(2, len(lst)+1): for perm in permutations(lst, i): if ''.join(perm)== str: return True return False # Driver code str = 'geeks'lst = ['for', 'ge', 'abc', 'ks', 'e', 'xyz'] print(checkList(str, lst)) |
Output:
True
Approach #2 : Python RegEx
# Python3 program to Check if given string can # be formed by concatenating string elements # of list import re def checkList(str, lst): r = re.compile("(?:" + "|".join(lst) + ")*$") if r.match(str) != None: return True return False # Driver code str = 'geeks'lst = ['for', 'ge', 'abc', 'ks', 'e'] print(checkList(str, lst)) |
Output:
True
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