LeetCode-E-Isomorphic Strings

題意

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.

解法

實現

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        if(s.size() != t.size()) return false;
        map<char,char> cmap;
        for(int i = 0; i < s.size(); ++i){
            if(cmap.count(s[i]) == 0){
                cmap.insert(pair<char,char>(s[i],t[i]));
            }else{
                if(cmap[s[i]] != t[i]) return false;
            }
        }
        map<char,char> bmap;
        for(int i = 0; i < t.size(); ++i){
            if(bmap.count(t[i]) == 0){
               bmap.insert(pair<char,char>(t[i],s[i])); 
            }else{
               if(bmap[t[i]] != s[i]) return false;
            }
        }
        return true; 
    }
};