Isomorphic Strings

Desicription

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:

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Input: s = "egg", t = "add"
Output: true

Example 2:

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Input: s = "foo", t = "bar"
Output: false

Example 3:

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Input: s = "paper", t = "title"
Output: true

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

Solution

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class Solution {
public:
    bool isIsomorphic(string s, string t) {
        vector<int> sIndex(256, 0);
        vector<int> tIndex(256, 0);
        for(int i = 0; s[i]; i++) {
            if(sIndex[s[i]] != tIndex[t[i]])
                return false;
            sIndex[s[i]] = i + 1;
            tIndex[t[i]] = i + 1;
        }
        return true;
    }
};