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.
import java.util.Arrays; public class Solution { public boolean isIsomorphic(String s, String t) { if(s.length()!=t.length()) return false; int[] map1 = new int[257]; int[] map2 = new int[257]; Arrays.fill(map1, -1); Arrays.fill(map2, -1); for(int i=0;i<s.length();i++){ if(map1[s.charAt(i)]==-1){ map1[s.charAt(i)] = t.charAt(i); }else{ if(map1[s.charAt(i)] != t.charAt(i)){ return false; } } if(map2[t.charAt(i)]==-1){ map2[t.charAt(i)] = s.charAt(i); }else{ if(map2[t.charAt(i)] != s.charAt(i)){ return false; } } } return true; } }