205. Isomorphic Strings
Easy
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.
Example 1:
Input: s ="egg",
t ="add"
Output: true
Example 2:
Input: s ="foo",
t ="bar"
Output: false
Example 3:
Input: s ="paper",
t ="title"
Output: true
Note:
You may assume both s and t have the same length.
package leetcode.easy; import java.util.HashMap; public class IsomorphicStrings { public boolean isIsomorphic(String s, String t) { if (s.length() != t.length()) { return false; } 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; } @org.junit.Test public void test() { String s1 = "egg"; String t1 = "add"; String s2 = "foo"; String t2 = "bar"; String s3 = "paper"; String t3 = "title"; System.out.println(isIsomorphic(s1, t1)); System.out.println(isIsomorphic(s2, t2)); System.out.println(isIsomorphic(s3, t3)); } }