标签：paper lse must input apt question amp iso tle
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.
//Time: O(n), Space: O(n) public boolean isIsomorphic(String s, String t) { if (s == null && t == null) { return true; } if (s == null || t == null) { return false; } if (s.length() != t.length()) { return false; } int[] mapS = new int[256]; int[] mapT = new int[256]; for (int i = 0; i < s.length(); i++) { if (mapS[s.charAt(i)] != mapT[t.charAt(i)]) { return false; } mapS[s.charAt(i)] = i + 1;//反例就是ab和aa,否则无法判断第一位有无出现过 mapT[t.charAt(i)] = i + 1; } return true; }
标签：paper lse must input apt question amp iso tle
原文地址：https://www.cnblogs.com/jessie2009/p/9810062.html
