# 问题 原题链接：[https://leetcode.com/problems/isomorphic-strings/](https://leetcode.com/problems/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. 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. ``` Note: - You may assume both s and t have the same length. # 分析过程 - 输入：两个长度相同的字符串 - 输出：两个字符串是否是同构的字符串 - 思路：使用两个 map 用来记录某个字符出现的索引，遍历字符串时判断当前遍历的字符在 map 中记录的索引是否相同，如果不同直接返回 false。 # 解决方法 ```cpp class Solution { public: bool isIsomorphic(string s, string t) { const char *a = s.c_str(); const char *b = t.c_str(); map<char, int> mapA, mapB; int len = (int)strlen(a); for (int i = 0; i < len; i++) { if (mapA[a[i]] != mapB[b[i]]) { return false; } // 使用i+1避免和原始的0重复 mapA[a[i]] = i + 1; mapB[b[i]] = i + 1; } return true; } }; ```