[leetcode]521. Longest Uncommon Subsequence I

题目链接

题目描述

Given a group of two strings, you need to find the longest uncommon subsequence of this group of two strings. The longest uncommon subsequence is defined as the longest subsequence of one of these strings and this subsequence should not be any subsequence of the other strings.

A subsequence is a sequence that can be derived from one sequence by
deleting some characters without changing the order of the remaining
elements. Trivially, any string is a subsequence of itself and an empty string is a subsequence of any string.

The input will be two strings, and the output needs to be the length of the longest uncommon subsequence. If the longest uncommon subsequence doesn’t exist, return -1.

Example 1:
Input: “aba”, “cdc”
Output: 3
Explanation: The longest uncommon subsequence is “aba” (or “cdc”), because “aba” is a subsequence of “aba”, but not a subsequence of any other strings in the group of two strings.

Note:

1. Both strings’ lengths will not exceed 100.
2. Only letters from a ~ z will appear in input strings.

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概要
给定两个字符串，找出其中最长的不相同的子串，这个子串是来源于其中一个字符串，且不同于另一个字符串的任意子串。
注意

1. 两个字符串的长度不超过 100。
2. 字符串仅包括 a~z 字符。

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思路
这题很简单，很明显如果两个字符串长度不同，那最长的字符串就是最长的字串，如果长度相同且字符串不相等，那这两个字符串都符合这里的字串要求。

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代码实现

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