How hard is LeetCode 522. Longest Uncommon Subsequence II?

LeetCode 522. Longest Uncommon Subsequence II is rated Medium on LeetCode.

What is the time complexity of LeetCode 522. Longest Uncommon Subsequence II?

The Python solution on this page runs in O(n^2 \times m), where n is the length of the list of strings, and m is the average length of the strings.

What is the space complexity of LeetCode 522. Longest Uncommon Subsequence II?

The Python solution on this page uses O(1) auxiliary space.

What topics does LeetCode 522. Longest Uncommon Subsequence II cover?

LeetCode 522. Longest Uncommon Subsequence II is tagged Array, Hash Table, Two Pointers, String and Sorting on LeetCode.

Longest Uncommon Subsequence II — LeetCode 522 Python Solution

MediumArrayHash TableTwo PointersStringSorting

Problem: #522
Pattern: Two Pointers
Reading time: 3 min
Source: leetcode.com

The problem

Given an array of strings strs, return the length of the longest uncommon subsequence between them. If the longest uncommon subsequence does not exist, return -1.

Example

Input: strs = ["aba","cdc","eae"]
Output: 3

Python solution

Python

class Solution:
    def findLUSlength(self, strs: List[str]) -> int:
        def check(s: str, t: str):
            i = j = 0
            while i < len(s) and j < len(t):
                if s[i] == t[j]:
                    i += 1
                j += 1
            return i == len(s)

        ans = -1
        for i, s in enumerate(strs):
            for j, t in enumerate(strs):
                if i != j and check(s, t):
                    break
            else:
                ans = max(ans, len(s))
        return ans

Complexity

Measure	Complexity
Time	O(n^2 \times m), where n is the length of the list of strings, and m is the average length of the strings
Space	O(1) auxiliary

Pattern: Two Pointers

Use the order already in the input to discard half the search space at every step. LeetCode 522. Longest Uncommon Subsequence II is filed here because LeetCode tags it Two Pointers, which is the vocabulary this hub collects.

The two pointers guide has the Python template for the pattern and the 201 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 522. Longest Uncommon Subsequence II?: LeetCode 522. Longest Uncommon Subsequence II is rated Medium on LeetCode.
What is the time complexity of LeetCode 522. Longest Uncommon Subsequence II?: The Python solution on this page runs in O(n^2 \times m), where n is the length of the list of strings, and m is the average length of the strings.
What is the space complexity of LeetCode 522. Longest Uncommon Subsequence II?: The Python solution on this page uses O(1) auxiliary space.
What topics does LeetCode 522. Longest Uncommon Subsequence II cover?: LeetCode 522. Longest Uncommon Subsequence II is tagged Array, Hash Table, Two Pointers, String and Sorting on LeetCode.