2559. Count Vowel Strings in Ranges

class Solution {
public:
    vector<int> vowelStrings(vector<string>& words, vector<vector<int>>& queries) {
        vector<int>ans;
        vector<int> v;
        int cnt=0;

        for(int i=0; i<words.size(); i++)
        {
            int n = words[i].size();
          if(words[i][0]=='a' || words[i][0]=='e' || words[i][0]=='o' || words[i][0]=='i' ||
                words[i][0]=='u')
               {
                   if((words[i][n-1]=='a' || words[i][n-1]=='e' || words[i][n-1]=='o' ||
                    words[i][n-1]=='i' || words[i][n-1]=='u'))

                   cnt++;
               }

               v.push_back(cnt);
        }


        for(int i=0; i<queries.size(); i++)
        {
            int n = queries[i][0];
            int m = queries[i][1];
            if(n==0)
                ans.push_back(v[m]);
            else
                ans.push_back(v[m]-v[n-1]);
        }
        return ans;
    }
};