leetcode-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.

For example,
Given “egg”, “add”, return true.

Given “foo”, “bar”, return false.

Given “paper”, “title”, return true.
Note:
You may assume both s and t have the same length.

主要考察匹配映射。字符最多256个。
代码：

class Solution {public:    bool isIsomorphic(string s, string t) {        int m[256]={0};        int n[256]={0};        int l=s.size();        for(int i=0; i < l; i++)        {            if(m[s[i]] != n[t[i]])            return false;            m[s[i]] = n[t[i]] = i+1;        }        return true;    }};