CODEWITHSUNDEEP
python
Jk128711
Jk128711

Reputation: 13

How to fix an error when I try to compare two lists using operators

I'm trying to pick out the longest set of characters in alphabetical order in a string. However I could not figure out how to compare two variables and I initially tried using len(str) for the two variables, current_biggest and rn_str.

However that lead to errors saying

'object of type 'int' has no len()'

I have then tried a few different work arounds until you see the current failed list comparison. Its odd because I can check if they're equal but not if one is longer than the other. Any advice on how to fix it as well as an additonal more efficent method would be appreciate. I'm new to coding and would like to soak up as much as possible.

s = 'abcdebjnmzkloppk'

for i in range(len(s)-1):
    current_biggest = ['m']

rn_str =['m']


if (s[i] >= s[i+1]) and (i < len(s)):
    rn_str = i
if rn_str >= current_biggest:
    current_biggest = rn_str
    del rn_str

print(current_biggest)

Upvotes: 0

Views: 281

Answers (3)

Rory Daulton
Rory Daulton

Reputation: 22544

The cause of the error is given in your error message: you are trying to compare an integer and a list.

Early in your code you define both current_biggest and rn_str to be lists of strings. But later in your code you reassign rn_str to i, which is an integer. Later you try to compare current_biggest and rn_str, which then have different types, so the comparison does not work.

You have no comments in your code, so your desired algorithm is not clear. Your problem description is also not clear, so I cannot give you more help. But your problem seems to be one of two common problems: find an increasing sub-sequence of a given sequence, where one problem requires the sub-sequence to be consecutive and the other does not. Clarify your problem then do a web search on it--both these problems have many answers on the web and on this very site.

Upvotes: 1

newbiedude
newbiedude

Reputation: 51

def isInAlphabeticalOrder(word):
    count = 0
    sorted_word = sorted(word)
    for i in range(len(word) - 1):
        if word[i] == sorted_word[i]:
            count += 1
    return word[:count+1], count

s = 'abcdefghij'    
g = 'abuizyhijkl'    
c = 'acb'

print(isInAlphabeticalOrder(s))
#returns the alphabetical string + the count of correct following letters
print(isInAlphabeticalOrder(g))
#abui, 3 
print(isInAlphabeticalOrder(c))
#ac 1

The count variable tells you how many letters in a given string are alphabetically ordered (from the beginning until the first not ordered letter).

Upvotes: 0

Abhilash Dindalkop
Abhilash Dindalkop

Reputation: 1

from itertools import count

def long_alphabet(input_string):
    maxsubstr = input_string[0:0] # empty slice (to accept subclasses of str)
    for start in range(len(input_string)): # O(n)
        for end in count(start + len(maxsubstr) + 1): # O(m)
            substr = input_string[start:end] # O(m)
            if len(substr) != (end - start):  # found duplicates or EOS
                break
            if sorted(substr) == list(substr):
                maxsubstr = substr
    return maxsubstr

bla = (long_alphabet(s))
print("Longest substring in alphabetical order is: %s" %bla)

Further details of solution consists in this link: Find the longest substring in alphabetical order

Upvotes: 0

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