[LeetCode] Longest Uncommon Subsequence I

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).

두 문자열 a,b 가 주어질 때 두 문자열이 같으면 -1 , 아니라면 두 문자열중 길이가 긴 값의 길이를 리턴하면 되는 문제이다.

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.

2.풀이

1. 두 문자열을 비교하여 같으면 -1 , 아니라면 두 문자열의 길이 중 최댓값을 리턴해준다.

/**
 * @param {string} a
 * @param {string} b
 * @return {number}
 */
const findLUSlength = function (a, b) {
  // 두 문자열이 같으면 -1 , 아니라면 두 문자열 중 길이가 긴 값을 리턴한다.
  return a === b ? -1 : Math.max(a.length, b.length);
};

3.결과