205. Isomorphic Strings

Easy

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.

解題

func isIsomorphic(s string, t string) bool {
    m := make(map[byte]byte)
    m2 := make(map[byte]byte)
    
    for i:= range(s) {
        if _,ok := m[s[i]]; ok {
            if m[s[i]]!=t[i] {
                return false
            }
        } else {
            m[s[i]] = t[i]
        }
    }
    
    for i:= range(t) {
        if _,ok := m2[t[i]]; ok {
            if m2[t[i]]!=s[i] {
                return false
            }
        } else {
            m2[t[i]] = s[i]
        }
    }
    
    return true
}