Updated: June 19th, 2023

#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main() {
    vector<char> letters;
    string str1;
    getline(cin, str1);
    char vowels[5] = {'a', 'e', 'i', 'o', 'u'};
    int vowelsCount = 0;
    for (size_t i = 0; i < str1.length(); ++i) {
        char currentChar = str1[i];
        letters.push_back(currentChar);
    }

    for (int i = 0; i < 5; i++) {
        for (int j = 0; j < letters.size(); j++) {
            if (vowels[i] == letters[j]) {
                vowelsCount++;
            }
        }
    }

    cout << "Number of vowels found: " << vowelsCount << endl;

    return 0;
}

At first, I made some variables, arrays, and vectors. And I then used getLine to receive the data from the user. Since we need to have vowels, I made an array including the vowels. After that, I made a for loop that push_back the individual letters into the vector for comparison with the vowels.

Using nested for loops, I could compare the vowels and the letters. Using vowelsCount++, it will count the vowels.

As a result, we can see the number of the vowels in a string or a name.