## [205\. Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/)

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`.

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:**

**Input:** s = "egg", t = "add"
**Output:** true

**Example 2:**

**Input:** s = "foo", t = "bar"
**Output:** false

**Example 3:**

**Input:** s = "paper", t = "title"
**Output:** true

**Constraints:**

- `1 <= s.length <= 5 * 104`
- `t.length == s.length`
- `s` and `t` consist of any valid ascii character.

class Solution {
public:
    bool isIsomorphic(string s, string t)
    {
        unordered_map<char, int> m1;
        unordered_map<char, int> m2;

        int n = t.size();

        for (int i = 0; i < n; i++)
        {
            if (m1[s[i]] != m2[t[i]])
            {
                return false;
            }
            m1[s[i]] = i + 1;
            m2[t[i]] = i + 1;
        }
        return true;
    }
};

:::success
- 時間複雜度：$O(n)$
- 空間複雜度：$O(n)$
:::