第75题 Isomorphic Strings

字符串匹配：字符映射与等价性判断

最新推荐文章于 2023-06-01 20:09:33 发布

原创最新推荐文章于 2023-06-01 20:09:33 发布 · 351 阅读

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本文探讨了如何通过哈希表实现字符串s与字符串t之间的字符映射，判断它们是否具备等价性。通过实例分析，解释了在字符映射规则下，如何确保所有字符的一一对应，且映射关系保持一致性的关键步骤。

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.

For example,
Given "egg", "add", return true.

Given "foo", "bar", return false.

Given "paper", "title", return true.

Note:
You may assume both s and t have the same length.

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Solution in C++: 双向hashtable

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        if(s.size()!=t.size()) return false;
        int idx=0;
        map<char, char> mp, rev_mp;
        map<char, char>::iterator it;
        while(idx<s.size()){
            it = mp.find(s[idx]);
            if(it!=mp.end()){
                char cur = it->second;
                if(t[idx]!=cur) return false;
            }
            else{
                it = rev_mp.find(t[idx]);
                if(it!=rev_mp.end()) return false;
                mp[s[idx]] = t[idx];
                rev_mp[t[idx]] = s[idx];
            }
            idx++;
        }
        return true;
    }
};