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Given two strings a
and b
, find the length of the longest uncommon subsequence between them.
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).
An uncommon subsequence between two strings is a string that is a subsequence of one but not the other.
Return the length of the longest uncommon subsequence between a
and b
. If the longest uncommon subsequence doesn't exist, return -1
.
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.
[Brainteaser]
[String]
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