LeetCode 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.

题目：看看两个单词是否同构。这是一个明显的hash表的问题，但是要注意没有两个字母对应着一个字母，但是同一个字母可以对着自己本身

class Solution {
public:
bool isIsomorphic(string s, string t) {
map<char, char> chChMap,chChMap2;
for (unsigned i = 0;i < s.size();++i)
{

if (chChMap.find(s[i]) == chChMap.end())
chChMap[s[i]] = t[i];
else if (t[i] != chChMap[s[i]])
return false;
if (chChMap2.find(t[i]) == chChMap2.end())
chChMap2[t[i]] = s[i];
else if (s[i] != chChMap2[t[i]])
return false;
}
return true;
}
};