Package g2001_2100.s2063_vowels_of_all_substrings

Class Solution

  • public class Solution
extends Object
    2063 - Vowels of All Substrings.

    Medium

    Given a string word, return the sum of the number of vowels ('a', 'e', 'i', 'o', and 'u') in every substring of word.

    A substring is a contiguous (non-empty) sequence of characters within a string.

    Note: Due to the large constraints, the answer may not fit in a signed 32-bit integer. Please be careful during the calculations.

    Example 1:

    Input: word = “aba”

    Output: 6

    Explanation: All possible substrings are: “a”, “ab”, “aba”, “b”, “ba”, and “a”.

    • “b” has 0 vowels in it

    • “a”, “ab”, “ba”, and “a” have 1 vowel each

    • “aba” has 2 vowels in it

    Hence, the total sum of vowels = 0 + 1 + 1 + 1 + 1 + 2 = 6.

    Example 2:

    Input: word = “abc”

    Output: 3

    Explanation: All possible substrings are: “a”, “ab”, “abc”, “b”, “bc”, and “c”.

    • “a”, “ab”, and “abc” have 1 vowel each

    • “b”, “bc”, and “c” have 0 vowels each

    Hence, the total sum of vowels = 1 + 1 + 1 + 0 + 0 + 0 = 3.

    Example 3:

    Input: word = “ltcd”

    Output: 0

    Explanation: There are no vowels in any substring of “ltcd”.

    Constraints:

    • 1 <= word.length <= 105
    • word consists of lowercase English letters.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • countVowels

        public long countVowels​(String word)