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Prashant Mishra @prashantrmishra

Optimizing Vowel Count Queries In O(n) Time Complexity

Calculate prefix[] in O(n) and get vowel counts in O(k). Solution: iterate words, update prefix[], then calculate result for each query using prefix[]. Vowel check: a,e,i,o,u.

Problem
TC: O(n) for calculating the prefix[] and O(k) for getting all the counts of the vowels in the given ranges

class Solution {
    public int[] vowelStrings(String[] words, int[][] queries) {
        int result[]  = new int[queries.length];
        int prefix[] = new int[words.length];
        int currentCount =0;
        for(int i=0;i<words.length;i++){
            String  s= words[i];
            currentCount+=check(s.charAt(0)) && check(s.charAt(s.length()-1)) ? 1:0;
            prefix[i] = currentCount;
        }
        for(int i = 0;i<queries.length;i++){
            int left = qu...