题目链接：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",244)">"bar",return false.
"paper",244)">"title",sans-serif; font-size:14px; line-height:30px">
Note:
You may assume both s and t have the same length.
// 29 / 29 test cases passed.
// Status: Accepted
// Runtime: 390 ms
// Submitted: 1 minute ago
public class Solution {
public boolean isIsomorphic(String s,String t) {
Map<Character,Character> sm = new HashMap<Character,Character>();
Map<Character,Character> tm = new HashMap<Character,Character>();
for (int i = 0; i < s.length(); i++) {
char char_s = s.charAt(i);
char char_t = t.charAt(i);
if(sm.get(char_s) == null) {
if(tm.get(char_t) == null) {
sm.put(char_s,char_t);
tm.put(char_t,char_s);
} else return false;
} else {
if(tm.get(char_t) == null) return false;
if(!(sm.get(char_s) == char_t && tm.get(char_t) == char_s))
return false;
}
}
return true;
}
}
