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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.
解法一：
public class Solution { public boolean isIsomorphic(String s, String t) { if(s == null || s.length() <= 1) return true; HashMap<Character, Character> map = new HashMap<Character, Character>(); for(int i = 0 ; i< s.length(); i++){ char a = s.charAt(i); char b = t.charAt(i); if(map.containsKey(a)){ if(map.get(a).equals(b)) continue; else return false; }else{ if(!map.containsValue(b)) map.put(a,b); else return false; } } return true; } }
reference：https://leetcode.com/discuss/36144/java-solution-using-hashmap
解法二：c++
class Solution { public: bool isIsomorphic(string s, string t) { int m1[256] = {0}, m2[256] = {0}, n = s.size(); for (int i = 0; i < n; ++i) { if (m1[s[i]] != m2[t[i]]) return false; m1[s[i]] = i + 1; m2[t[i]] = i + 1; } return true; } };
reference：https://leetcode.com/discuss/33854/my-6-lines-solution
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原文地址：http://www.cnblogs.com/hygeia/p/5088443.html
