[LeetCode 解题报告]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.

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        if (s.length() != t.length())
            return false;
        
        vector<int> m(128, 0), n(128, 0);
        for (int i = 0; i < s.length(); i ++) {
            if (m[s[i]] != n[t[i]])
                return false;
            m[s[i]] = i+1;
            n[t[i]] = i+1;
        }
        return true;
    }
};