【EASY】Isomorphic Strings

发布于: 2019-03-06 20:10
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问题

原题链接: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

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;
    }
};

Thanks for reading.

All the best wishes for you! 💕