Longest Common Subsequence in Python

Welcome to the Longest Common Subsequence in Python page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

import sys


def input_list(list_str):
    return [int(x.strip(" "), 10) for x in list_str.split(',')]


def longest(s1, s2):
    return s1 if len(s1) > len(s2) else s2


def lcs(s1, s2):
    if len(s1) == 0 or len(s2) == 0:
        return []
    elif s1[-1] == s2[-1]:
        return lcs(s1[:-1], s2[:-1]) + [s1[-1]]
    elif s1[-1] != s2[-1]:
        return longest(lcs(s1, s2[:-1]), lcs(s1[:-1], s2))


def exit_with_error():
    print('Usage: please provide two lists in the format "1, 2, 3, 4, 5"')
    sys.exit(1)


def main(args):
    try:
        lst1 = input_list(args[0])
        lst2 = input_list(args[1])
        print(lcs(lst1, lst2))
    except (IndexError, ValueError):
        exit_with_error()


if __name__ == "__main__":
    main(sys.argv[1:])

Longest Common Subsequence in Python was written by:

• Boot-Error
• Parker Johansen

If you see anything you'd like to change or update, please consider contributing.

Note: The solution shown above is the current solution in the Sample Programs repository as of Mar 21 2019 16:33:32. The solution was first committed on Oct 16 2018 08:04:37. As a result, documentation below may be outdated.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.