/**

* @program JavaBooks

* @description: 同构字符串

* @author: mf

* @create: 2020/04/10 19:59

*/

package subject.hash;

import java.util.HashMap;

/**

* 输入: s = "egg", t = "add"

* 输出: true

* 输入: s = "foo", t = "bar"

* 输出: false

* 输入: s = "paper", t = "title"

* 输出: true

*/

public class T0 {

public boolean isIsomorphic(String s, String t) {

return isomerphic(s, t) && isomerphic(t, s);

}

private boolean isomerphic(String s, String t) {

int n = s.length();

HashMap<Character, Character> map = new HashMap<>();

for (int i = 0; i < n; i++) {

Character c1 = s.charAt(i);

Character c2 = t.charAt(i);

if (map.containsKey(c1)) {

if (map.get(c1) != c2) {

return false;

}

} else {

map.put(c1, c2);

}

}

return true;

}

}