Reformat Date

<-E 1507> Reformat Date

class Solution {
public:
    string reformatDate(string date) {
       int n = date.length();
        vector<string>arr{"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"};
        string m,d,y;
        for(int i=0 ; i<12 ; i++)
            if(date.find(arr[i])!=string::npos) m = to_string(i+1);
        if(m.length()<2) m = "0"+m;
        
        y = date.substr(n-4,n);
        for(int i=0 ; i<3 ; i++)
        {
            if(isdigit(date[i])) 
                d += date[i];
            else break;
        }
        if(d.length() < 2) d = "0"+d;
        return y + "-" + m + "-" + d; 
    }
};