LeetCode-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"
, "bar"
, return false.
Given "paper"
, "title"
, return true.
Note:
You may assume both s and t have the same length.
Analysis:
Be careful that the chars should be 1-on-1 mapping.
Solution:
public class Solution { public boolean isIsomorphic(String s, String t) { if (s.length()!=t.length()) return false; if (s.length()==0) return true; Character[] charMap = new Character[128]; boolean[] mapped = new boolean[128]; char[] sArr = s.toCharArray(); char[] tArr = t.toCharArray(); for (int i=0;i<sArr.length;i++){ if (charMap[sArr[i]]==null){ if (mapped[tArr[i]]) return false; charMap[sArr[i]] = tArr[i]; mapped[tArr[i]] = true; } else { if (charMap[sArr[i]]!=tArr[i]) return false; } } return true; } }