All problems

Isomorphic Strings

Easy · hash map

You are given two strings s and t of the same length. Think of renaming letters: pick a letter that appears in s and replace every copy of it with some other letter. Do this for as many letters as you like, all at once. A letter may also keep its own name.

The renaming must be one-to-one: two different letters of s can never end up with the same new letter.

Return true if some renaming turns s into exactly t, and false otherwise.

Examples

Example 1

Input: s = "egg", t = "add"

Output: true

Rename e to a and g to d. Both g's change together.

Example 2

Input: s = "foo", t = "bar"

Output: false

Both o's in s must change to the same letter, but they line up with a and r.

Example 3

Input: s = "ab", t = "aa"

Output: false

a and b would both have to become a, and a renaming may not merge two letters.

Constraints

• 1 <= len(s) <= 10^4
• len(t) == len(s)
• s and t contain only lowercase English letters.