Longest substring of vowels

Given a string s of lowercase letters, we need to find the longest substring length that contain (a, e, i, o, u) only.

Examples :-

Input : s = "geeksforgeeks"
Output : 2
Longest substring is "ee"

Input : s = "theeare"
Output : 3

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

The idea is to traverse the string and keep track of current number of vowels in the string. If we see a character that is not vowel, we reset count to 0. But before resetting we update max count value which is going to be our result.

C++

// CPP program to find the  
// longest substring of vowels. 
#include <bits/stdc++.h> 
using namespace std; 
  
bool isVowel(char c) 
{ 
    return (c == 'a' || c == 'e' || c == 'i' 
            || c == 'o' || c == 'u'); 
             
} 
  
int longestVowel(string s) 
{ 
    int count = 0, res = 0; 
    for (int i = 0; i <= s.length(); i++)  
    { 
  
        // Increment current count 
        // if s[i] is vowel  
        if (isVowel(s[i]))  
        count++;      
  
        else 
        { 
  
            // check previous value  
            // is greater then or not 
            res = max(res, count); 
  
            count = 0; 
        } 
    } 
    return res; 
} 
  
// Driver code 
int main() 
{ 
    string s = "theeare"; 
    cout << longestVowel(s) << endl; 
    return 0; 
} 

Java

// Java program to find the  
// longest substring of vowels. 
import java.util.*; 
  
class GFG 
{ 
  
    static boolean isVowel(char c) 
    { 
        return (c == 'a' || c == 'e' || c == 'i' 
                 || c == 'o' || c == 'u'); 
    } 
  
    static int longestVowel(String str) 
    { 
        int count = 0, res = 0; 
        char[] s = str.toCharArray(); 
          
        for (int i = 0; i < s.length; i++)  
        { 
  
            // Increment current count  
            // if s[i] is vowel  
            if (isVowel(s[i]))  
            count++;      
  
            else 
            { 
                // check previous value  
                // is greater then or not 
                res = Math.max(res, count); 
  
                count = 0; 
            } 
        } 
          
    return res; 
    } 
  
// Driver code 
public static void main (String[] args)  
{ 
    String s = "theeare"; 
    System.out.println(longestVowel(s)); 
} 
} 
// This code is contributed by Mr. Somesh Awasthi 

C#

// C# program to find the  
// longest substring of vowels. 
using System; 
  
class GFG 
{ 
  
    static bool isVowel(char c) 
    { 
        return (c == 'a' || c == 'e' || c == 'i'  
                || c == 'o' || c == 'u'); 
    } 
  
    static int longestVowel(String str) 
    { 
        int count = 0, res = 0; 
        char []s = str.ToCharArray(); 
          
        for (int i = 0; i < s.Length; i++)  
        { 
  
            // Increment current count 
            // if s[i] is vowel  
            if (isVowel(s[i]))  
            count++;      
  
            else 
            { 
                // check previous value 
                // is greater then or not 
                res = Math.Max(res, count); 
  
                count = 0; 
            } 
        } 
          
    return res; 
    } 
  
// Driver code 
public static void Main ()  
    { 
        String s = "theeare"; 
        Console.Write(longestVowel(s)); 
    } 
} 
  
// This code is contributed by nitin mittal 

Output:

This article is contributed by Ajay Puri. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

C#

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