Given a string str and an integer X, the task is to find and print the first X vowels from str. If the total vowels in str is < X then print -1.
Examples:
Input: str = “GeeksForGeeks”, X = 3
Output: eeo
‘e’, ‘e’ and ‘o’ are the first three vowels in the given string.Input: str = “softcopy”, X = 5
Output: -1
The total vowel count is 2 i.e ‘o’ and ‘o’
Approach: Traverse the string character by character and check if the current character is a vowel. If the current character is a vowel, then concatenate it to the resultant string, result. If at any point the length of the resultant string becomes X then print the string result else print -1 in the end.
Below is the implementation of the above approach:
C++
// C++ implementation of the approach#include <bits/stdc++.h>using namespace std;// Function to check if a character is vowelbool isVowel(char c){ c = tolower(c); if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') return true; return false;}// Function to return first X vowelsstring firstXvowels(string s, int x){ // String to store first X vowels string result = ""; for (int i = 0; i < s.length(); i++) { // If s[i] is a vowel then // append it to the result if (isVowel(s[i])) result += s[i]; // If the desired length is reached if (result.length() == x) { return result; } } // If total vowels are < X return "-1";}// Driver codeint main(){ string str = "GeeksForGeeks"; int x = 3; cout << firstXvowels(str, x); return 0;} |
Java
// Java implementation of the approach public class GFG{ // Function to check if a character is vowel static boolean isVowel(char c) { c = Character.toLowerCase(c) ; if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') return true; return false; } // Function to return first X vowels static String firstXvowels(String s, int x) { // String to store first X vowels String result = ""; for (int i = 0; i < s.length(); i++) { // If s[i] is a vowel then // append it to the result if (isVowel(s.charAt(i))) result += s.charAt(i); // If the desired length is reached if (result.length() == x) { return result; } } // If total vowels are < X return "-1"; } // Driver code public static void main(String []args) { String str = "GeeksForGeeks"; int x = 3; System.out.println(firstXvowels(str, x)) ; } // This code is contributed by Ryuga } |
Python3
# Python 3 implementation of the approach# Function to check if a character is voweldef isVowel(c): c = c.lower() if (c == 'a' or c == 'e' or c == 'i' or c == 'o' or c == 'u'): return True return False# Function to return first X vowelsdef firstXvowels(s, x): # String to store first X vowels result = "" for i in range(0, len(s), 1): # If s[i] is a vowel then # append it to the result if (isVowel(s[i])): result += s[i] # If the desired length is reached if (len(result) == x): return result # If total vowels are < X return "-1"# Driver codeif __name__ == '__main__': str = "GeeksForGeeks" x = 3 print(firstXvowels(str, x))# This code is implemented by# Surendra_Gangwar |
C#
// C# implementation of the approach using System;class GFG{// Function to check if a // character is vowel static bool isVowel(char c) { c = Char.ToLower(c) ; if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') return true; return false; } // Function to return first X vowels static string firstXvowels(string s, int x) { // String to store first X vowels string result = ""; for (int i = 0; i < s.Length; i++) { // If s[i] is a vowel then // append it to the result if (isVowel(s[i])) result += s[i]; // If the desired length is reached if (result.Length == x) { return result; } } // If total vowels are < X return "-1"; } // Driver code public static void Main(){ string str = "GeeksForGeeks"; int x = 3; Console.WriteLine(firstXvowels(str, x)) ; } }// This code is contributed // by Akanksha Rai |
PHP
<?php// PHP implementation of the approach// Function to check if a character is vowelfunction isVowel($c){ $c = strtolower($c); if ($c == 'a' || $c == 'e' || $c == 'i' || $c == 'o' || $c == 'u') return true; return false;}// Function to return first X vowelsfunction firstXvowels($s, $x){ // String to store first X vowels $result = ""; for ($i = 0; $i < strlen($s); $i++) { // If s[i] is a vowel then // append it to the result if (isVowel($s[$i])) $result .= $s[$i]; // If the desired length is reached if (strlen($result) == $x) { return $result; } } // If total vowels are < X return "-1";}// Driver code$str = "GeeksForGeeks";$x = 3;echo firstXvowels($str, $x);// This code is contributed // by princiraj1992?> |
Javascript
<script>// Javascript implementation of the approach// Function to check if a character is vowelfunction isVowel(c){ c = (c.toLowerCase()); if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u') return true; return false;}// Function to return first X vowelsfunction firstXvowels(s, x){ // String to store first X vowels var result = ""; for (var i = 0; i < s.length; i++) { // If s[i] is a vowel then // append it to the result if (isVowel(s[i])) result += s[i]; // If the desired length is reached if (result.length == x) { return result; } } // If total vowels are < X return "-1";}// Driver codevar str = "GeeksForGeeks";var x = 3;document.write( firstXvowels(str, x));</script> |
Output
eeo
Complexity Analysis:
- Time Complexity: O(n) Here, n is the length of the string.
- Auxiliary Space: O(x) Where x is the no of vowels in the string
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