LC version: https://leetcode.com/problems/string-transforms-into-another-string (premium)\n\nGiven 2 strings `s` and `t`, determine if you can convert `s` into `t`. The rules are:\n1. You can change 1 letter at a time.\n2. Once you changed a letter you have to change **all occurrences** of that letter.\n\n**Example 1:**\n```\nInput: s = "abca", t = "dced"\nOutput: true\nExplanation: abca (\'a\' to \'d\') -> dbcd (\'c\' to \'e\') -> dbed (\'b\' to \'c\') -> dced\n```\n\n**Example 2:**\n```\nInput: s = "ab", t = "ba"\nOutput: true\nExplanation: ab -> ac -> bc -> ba\n```\n\n**Example 3:**\n```\nInput: s = "abcdefghijklmnopqrstuvwxyz", t = "bcdefghijklmnopqrstuvwxyza"\nOutput: false\n```\n\n**Example 4:**\n```\nInput: s = "aa", t = "cd"\nOutput: false\n```\n\n**Example 5:**\n```\nInput: s = "ab", t = "aa"\nOutput: true\n```\n\n**Example 6:**\n```\nInput: s = "abcdefghijklmnopqrstuvwxyz", t = "bbcdefghijklmnopqrstuvwxyz"\nOutput: true\n```\n\nBoth strings contain only lowercase English letters.

LC version: https://leetcode.com/problems/string-transforms-into-another-string (premium)\n\nGiven 2 strings s and t, determine if you can convert s into t. The