Leetcode Solution - 205. Isomorphic Strings

IsIsomorphic.cs

public class Solution {
    public bool IsIsomorphic(string s, string t) {
            var length = s.Length;
            var dict = new Dictionary<char, char>();
            for (var i = 0; i < length; ++i)
                if (dict.ContainsKey(s[i]))
                {
                    if (dict[s[i]] != t[i]) return false;
                }
                else
                {
                    if (dict.ContainsValue(t[i])) return false;
                    dict.Add(s[i], t[i]);
                }

            return true;
    }
}

// Result: https://leetcode.com/submissions/detail/572834603/

LeetCode 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.