26 January Case-specific Sorting of Strings

class Solution
{
    public:
    //Function to perform case-specific sorting of strings.
     string caseSort(string str, int n)

    {

        vector<char> m1;
        vector<char> m2;
        string res="";
        for(int i=0; i<n; i++)

        {

            if(str[i]>='a' && str[i]<='z')

            {

                m1.push_back(str[i]);

            }

            else

            {

                m2.push_back(str[i]);

            }

        }

        sort(m1.begin(),m1.end());
        sort(m2.begin(),m2.end());
        int j=0,k=0;
        for(int i=0; i<n; i++)

        {

            if(str[i]>='a' && str[i]<='z')

            {

                res+=m1[j];

                j++;

            }

            else

            {

                res+=m2[k];

                k++;

            }

        }

        return res;
    }
};