1192. Longest Uncommon Subsequence I

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.

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

您在真实的面试中是否遇到过这个题？  是

样例

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.

这个题目写了这么长，解释了半天，最后惊讶地发现，如果两个字符串相同，就没有最长的非常见子序列；如果相同，最长的非常见子序列就是较长的那个字符串。

class Solution {
public:
    /**
     * @param a: a string
     * @param b: a string
     * @return: return a integer
     */
    int findLUSlength(string &a, string &b) {
        // write your code here
        return a == b ? -1 : max(a.size(), b.size());
    }
};