What is the difference between "" and ""?


  • 2
    D

    I am not sure what exactly is going wrong here. I am using Trie, the rest is self explanatory:

    const int ALPH_SIZE = 256;
    
    struct Node{
        char ch;
        bool isWord;
        vector<Node *> links;
    
        Node(){
            ch = 0;
            isWord = false;
            links.resize(ALPH_SIZE,NULL);
        }
    };
    
    class Trie{
        Node * myRoot;
    
        public:
            int myCount;
        Trie(){
            myRoot = new Node();
            myCount = 1;
        }
        void insert(const string &s){
            int len = s.size();
            Node *t = myRoot;
            for(int i = 0; i < len; ++i){
                if(t->links[s[i]] == NULL){
                    t->links[s[i]] = new Node();
                    t = t->links[s[i]];
                    t->ch = s[i];
                    ++myCount;
                }
            }
            t->isWord = true;
        }
    
        string solve(){
           Node *t = myRoot;
           string ret = "";
           while(t->isWord){
    
              int cnt = 0, index = 0;
              for(int i = 0; i < 256; ++i){
                if(t->links[i] != NULL){ index = i; cnt++;}
              }
              if(cnt != 1) return ret;
               t = t->links[index];
              ret += char(t->ch);
           }
           ret += char(t->ch);
    
           return ret;
        }
    };
    
    class Solution {
    public:
        string longestCommonPrefix(vector<string> &strs) {
            
            string ret = "";
            if(strs.size() == 1) return strs[0];
            if(strs.size() == 0) return ret;
            Trie* myTrie;
            myTrie = new Trie();
            for(int i = 0; i < strs.size(); ++i){
               myTrie->insert(strs[i]);
               if(strs[i].size() == 0) return ret;
            }
            return(myTrie->solve());   
               
        }
    };
    

    I am getting a wrong answer in this manner:

    Input: ["a","b"]
    Output: ""
    Expected: ""

    what exactly am I missing here?


  • 0
    M

    I met the same issue, does any one know the reason?


  • 0
    P

    Maybe your answer is "\0", but the expected answer is "".


  • 0
    A

    i got the same message. but it is actually 'runtime error', not 'error answer'.


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