longestWord.txt

524. Longest Word in Dictionary through Deleting

Given a string s and a string array dictionary, 
return the longest string in the dictionary that can be formed by deleting some of the given string characters.
If there is more than one possible result, return the longest word with the smallest lexicographical order. 
If there is no possible result, return the empty string.

class Solution {
public:
    bool isSubsequence(string sub, string super){
        int i = 0 , j = 0;
        while(i < sub.size() && j < super.size()){
            if(sub[i]==super[j]){
                i++;
            }
            j++;
        }
        if(i == sub.size()) return true;
        else return false;
    }

    string findLongestWord(string s, vector<string>& dictionary) {
        string res = "";
        for(string& word : dictionary){
            if(word.size() > res.size() || (word.size() == res.size() && word < res)){
                if(isSubsequence(word, s)){
                    res = word;
                }
            }
        }
        return res;
    }
};