Day 17 of 100 Days of DSA

Day 17: Sorting Vowels in a String

Today, as part of my 100 days of DSA challenge, I tackled a medium-level problem from LeetCode. The task was to sort the vowels in a given string. Let me walk you through how I approached and solved this problem.

Firstly, I created an empty string called vowel to store all the vowels from the given input string. I used a loop to iterate through each character in the input string. If the character was a vowel (either lowercase or uppercase), I added it to the vowel string.

After collecting all the vowels, I sorted them in non-decreasing order using the sort function.

Now, I needed to replace the original string's vowels with the sorted vowels. To do this, I used another loop to traverse the original string. If the current character was a vowel, I replaced it with the corresponding character from the sorted vowel string. I kept track of my position in the sorted vowel string using an index variable j.

Here's a breakdown of the code:

class Solution {
public:
    string sortVowels(string str) {
        // Step 1: Collect vowels from the given string
        string vowel = "";
        for(int i = 0; i < str.size(); i++) {
            if(str[i] == 'a' || str[i] == 'e' || str[i] == 'i' || str[i] == 'o' || str[i] == 'u' ||
               str[i] == 'A' || str[i] == 'E' || str[i] == 'I' || str[i] == 'O' || str[i] == 'U') {
                vowel += str[i];
            }
        }

        // Step 2: Sort the collected vowels
        sort(vowel.begin(), vowel.end());

        // Step 3: Replace original string's vowels with sorted vowels
        int j = 0;
        for(int i = 0; i < str.size(); i++) {
            if(str[i] == 'a' || str[i] == 'e' || str[i] == 'i' || str[i] == 'o' || str[i] == 'u' ||
               str[i] == 'A' || str[i] == 'E' || str[i] == 'I' || str[i] == 'O' || str[i] == 'U') {
                str[i] = vowel[j++];
            }
        }

        // Step 4: Return the modified string
        return str;
    }
};

In summary, this code efficiently sorts the vowels in a given string by collecting them, sorting them, and then replacing the original string's vowels with the sorted ones.