# Problem Definition

## Description

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

Two strings are isomorphic if the characters in **s** can be replaced to get **t**.

All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.

**Example 1:**

```plaintext
Input: s = "egg", t = "add"
Output: true
```

**Example 2:**

```plaintext
Input: s = "foo", t = "bar"
Output: false
```

**Example 3:**

```plaintext
Input: s = "paper", t = "title"
Output: true
```

**Note:**
You may assume both **s** and **t** have the same length.

## Notes

1. [LeetCode discussion - Java solution using HashMap](https://leetcode.com/problems/isomorphic-strings/discuss/57802/Java-solution-using-HashMap)