Problem:

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.

Summary:

判断所给出的两个字符串是否为相同格式。

Solution:

解法同

1 class Solution { 2 public: 3     bool isIsomorphic(string s, string t) { 4         int len = s.size(); 5         unordered_map
     
       m; 6         for (int i = 0; i < len; i++) { 7             if (m.find(s[i]) == m.end()) { 8                 m[s[i]] = t[i]; 9             }10             else if (m[s[i]] != t[i]){11                 return false;12             }13         }14         15         for (unordered_map
      
       ::iterator i = m.begin(); i != m.end(); i++) {16             for (unordered_map
       
        ::iterator j = m.begin(); j != m.end(); j++) {17                 if (i->first != j->first && i->second == j->second) {18                     return false;19                 }20             }21         }22         return true;23     }24 };