929. Unique Email Addresses

發表於 | 分類於

problem

solution

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
class Solution {
public:
    string process(string str){
        string local_name , domain_name;
        int i = 0;
        while(str[i]!='@'){
            if(str[i]=='+') break;
            else if(str[i]!='.') local_name += str[i];
            i++;
        }
        while(str[i]!='@') i++;
        i++;
        while(i<str.size()) domain_name+=str[i++];
        
        string ans = local_name + "@"+domain_name;
        return ans;
    }
    int numUniqueEmails(vector<string>& emails) {
        unordered_set<string> s;
        for(string strs:emails) s.insert(process(strs));
        return s.size();
        
    }
};

analysis

  • time complexity O(nm)
  • space complexity O(nm)