Longest Common String (Test Case #4)

Question

I have done my code,but Test Case #4 failed.I can't find the bug, could you hepl me ?
My code url:
https://code.sololearn.com/cjl34y2071rd

Task:
Given multiple words, you need to find the longest string that is a substring of all words.

Input Format:
A string of words, separated by spaces. The string can also contain numbers.

Output Format:
A string, representing the longest common substring.
If there are multiple longest common substrings, output the smallest one in alphabetical order.

Sample Input:
SoloLearn Learning LearningIsFun Learnable

Sample Output:
Learn

Answer 1

1. Split string
2. Sort array
3. Sort array by length of the items in reverse order
4. Take the first one

Answer 2

Thank you for your help, it works when I used your suggestion. And I really want to know,why sort by length can pass the Test Case #4.Looking forward to your reply.

Answer 3

My solution od this task:

import re
from itertools import combinations

string = input().split(" ")

def common_string(string):

string_list = combinations(string, 2)
substring = []

for strings in string_list:

y = 0
z = 1

while z <= len(strings[0]) - 1:

if re.search(strings[0][y : z], strings[1]):

string = strings[0][y : z]

if z == len(strings[0]) - 1:
if re.search(strings[0][y :], strings[1]):
string = strings[0][y :]

z += 1

else:

y = z - 1
z += 1

substring.append(string)

if len(set(substring)) == 1:
print("".join(set(substring)))

else:
common_string(set(substring))

common_string(string)

Answer 4

Hi guys, I have a similar issue.

# Check if the length of the result is greater than one or print the result

if len(commons) > 1:
commons = list(sorted(commons, key=str.lower))
commons = list(sorted(commons, key=len, reverse=True))

lens = [len(x) for x in commons]

maxlen = max(lens)

maxcount = lens.count(maxlen)

if maxcount > 1:
maxcoms = [x for x in commons if len(x) == maxlen]
maxcoms = list(sorted(maxcoms, key=str.lower))
print(maxcoms[0])
else:
print(commons[0])
else:
print(commons[0])

Answer 5

Failing test case 4

Answer 6

# Grab input and split to list

str_input = input().split(" ")

def mutate(x):
"""
Creates all possible permutations for a
given string.
"""
start = 0

while start < len(x):
i = 0
end = 1
while i < len(x):
yield x[start:end]
end += 1
i += 1
start += 1

# List to hold all possible permutations

mutations = []

# Run generator function on all list elememts and append to mutations list

for i in str_input:
for j in mutate(i):
mutations.append(j)

# List to hold common permutations

commons = []

# Find words that occur in each list item

for i in mutations:
common = set([x for x in str_input if(i in x)])
if len(common) == len(str_input):
commons.append(i)

# Check if the length of the result is greater than one or print the result

if len(commons) > 1:
commons = list(sorted(commons, key=str.lower))
commons = list(sorted(commons, key=len, reverse=True))