Destination City.cpp

class Solution {
public:
    string destCity(vector<vector<string>>& paths) {
        map<string,int>mp;
        for(auto it:paths)
        {
            mp[it[0]]++;
        }
        for(auto it:paths)
        {
            if(mp.find(it[1])==mp.end())
            return it[1];
        }
        return "";
    }
};