題目：

anysubsequence 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.

代碼：

題目意思是找出給定的兩個字符串最長的不相同子串長度，所以如果兩個字符串相同，return -1；如果兩個字符串不同，則為較長的字符串的長度。

自己的：

1 class Solution {
2 public:
3     int findLUSlength(string a, string b) {
4         int result = -1;
5         if (a != b)
6             result = max(a.size(), b.size());
7         return result;
8     }
9 };

別人的：

 1
 
 class Solution {
 2 public:
 3     int findLUSlength(string a, string b) {
 4         
 5         if ( a.size() != b.size() ) {
 6             return( max( a.size(), b.size() ) );
 7         }
 8         int len = -1;
 9         if ( a.compare( b ) != 0 ) {
10             len = a.size();
11         }
12         return len;
13     }
14 };

LeetCode： 521 Longest Uncommon Subsequence I(easy)