Given two strings `s` and `t`, determine if they are isomorphic.
Two strings `s` and `t` are isomorphic if the characters in `s` can be replaced to get `t`, with the following rules:
- Each character in `s` maps to exactly one character in `t`.
- No two characters in `s` map to the same character in `t`.
- The order of characters is preserved.
Example 1
Input:s = "egg", t = "add"
Output:true
Explanation:e -> a, g -> d. The mapping is consistent.
Example 2
Input:s = "foo", t = "bar"
Output:false
Explanation:o maps to both a and r, which is not allowed.
Example 3
Input:s = "paper", t = "title"
Output:true
Constraints
- 1 <= s.length <= 5 * 10^4
- t.length == s.length
- s and t consist of any valid ASCII character.