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:
class Solution {
public:
bool isIsomorphic(string s, string t) {
int len = s.size();
unordered_map<char, char> m;
for (int i = ; i < len; i++) {
if (m.find(s[i]) == m.end()) {
m[s[i]] = t[i];
}
else if (m[s[i]] != t[i]){
return false;
}
}
for (unordered_map<char, char>::iterator i = m.begin(); i != m.end(); i++) {
for (unordered_map<char, char>::iterator j = m.begin(); j != m.end(); j++) {
if (i->first != j->first && i->second == j->second) {
return false;
}
}
}
return true;
}
};