README_EN.md

521. Longest Uncommon Subsequence I

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Description

Given two strings a and b, return the length of the longest uncommon subsequence between a and b. If the longest uncommon subsequence does not exist, return -1.

An uncommon subsequence between two strings is a string that is a subsequence of one but not the other.

A subsequence of a string s is a string that can be obtained after deleting any number of characters from s.

• For example, "abc" is a subsequence of "aebdc" because you can delete the underlined characters in "aebdc" to get "abc". Other subsequences of "aebdc" include "aebdc", "aeb", and "" (empty string).

 

Example 1:

Input: a = "aba", b = "cdc"
Output: 3
Explanation: One longest uncommon subsequence is "aba" because "aba" is a subsequence of "aba" but not "cdc".
Note that "cdc" is also a longest uncommon subsequence.

Example 2:

Input: a = "aaa", b = "bbb"
Output: 3
Explanation: The longest uncommon subsequences are "aaa" and "bbb".

Example 3:

Input: a = "aaa", b = "aaa"
Output: -1
Explanation: Every subsequence of string a is also a subsequence of string b. Similarly, every subsequence of string b is also a subsequence of string a.

 

Constraints:

• 1 <= a.length, b.length <= 100
• a and b consist of lower-case English letters.

Solutions

Python3

class Solution:
    def findLUSlength(self, a: str, b: str) -> int:
        return -1 if a == b else max(len(a), len(b))

Java

class Solution {
    public int findLUSlength(String a, String b) {
        return a.equals(b) ? -1 : Math.max(a.length(), b.length());
    }
}

TypeScript

function findLUSlength(a: string, b: string): number {
    return a != b ? Math.max(a.length, b.length) : -1;
}

Rust

impl Solution {
    pub fn find_lu_slength(a: String, b: String) -> i32 {
        if a == b {
            return -1;
        }
        a.len().max(b.len()) as i32
    }
}

C++

class Solution {
public:
    int findLUSlength(string a, string b) {
        return a == b ? -1 : max(a.size(), b.size());
    }
};

Go

func findLUSlength(a string, b string) int {
	if a == b {
		return -1
	}
	if len(a) > len(b) {
		return len(a)
	}
	return len(b)
}

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