205. Isomorphic Strings

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:

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

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

# @param {String} s
# @param {String} t
# @return {Boolean}
def is_isomorphic(s, t)
  
  return false if s.size != t.size
  
  hash1 = {}
  hash2 = {}
  
  for i in 0..s.size do
    
    curn1 = s[i]
    curn2 = t[i]
    
    if hash1[curn1].nil?
      hash1[curn1] = curn2
    elsif hash1[curn1] != curn2
      return false
    end
    
    if hash2[curn2].nil?
      hash2[curn2] = curn1
    elsif hash2[curn2] != curn1
      return false
    end
  end
  
  return true
  
end