135. Isomorphic Strings

Easy · String

Two strings are isomorphic if the characters in one string can be replaced to get the other string, while preserving the order of characters. A character must map to exactly one other character, and no two characters may map to the same character.

Given two strings s and t, determine if they are isomorphic.

Examples

Example 1
Input: s = "egg", t = "add"
Output: true
Explanation: The mapping e → a, g → d is valid and consistent. Each character in s maps to exactly one character in t.
Example 2
Input: s = "badc", t = "baba"
Output: false
Explanation: The character 'a' in s would need to map to both 'a' and 'b' in t, which violates the isomorphic property.

Constraints