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.
// 判断两个字符是否可以直接映射
算法
o(n)
class Solution {
public:
bool isIsomorphic(string s, string t) {
if(s.size()!=t.size()) return false;
const int MAXCHAR = 256;
char maps[MAXCHAR]={0}, mapt[MAXCHAR]={0};
for(int i=0;i<s.size();i++){
if(maps[s[i]]==0 && mapt[t[i]]==0){
maps[s[i]]=t[i];
mapt[t[i]]=s[i];
continue;
}
if(maps[s[i]]==t[i] && mapt[t[i]]==s[i])
continue;
return false;
}
return true;
}
};