Longest substring of vowels

13 Mar, 2022
Given a string s of lowercase letters, we need to find the longest substring length that contains (a, e, i, o, u) only. 
Examples : 
Input: s = "geeksforgeeks"
Output: 2
Longest substring is "ee"

Input: s = "theeare"
Output: 3
The idea is to traverse the string and keep track of the current number of vowels in the string. If we see a character that is not a vowel, we reset count to 0. But before resetting we update the max count value which is going to be our result. 
C++
Java
Python3
C#
PHP
Javascript
// 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 max(res, count);} // Driver codeint main(){    string s = "theeare";    cout << longestVowel(s) << endl;    return 0;}
// 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 Math.max(res, count);    } // Driver codepublic static void main (String[] args){    String s = "theeare";    System.out.println(longestVowel(s));}}// This code is contributed by Mr. Somesh Awasthi
# Python3 program to find the# longest substring of vowels.def isVowel(c):    return (c == 'a' or c == 'e' or            c == 'i' or c == 'o' or            c == 'u')           def longestVowel(s):    count, res = 0, 0         for i in range(len(s)):         # Increment current count        # if s[i] is vowel        if (isVowel(s[i])):            count += 1          else:                    # check previous value            # is greater then or not            res = max(res, count)             count = 0    return max(res, count) # Driver codeif __name__ == "__main__":    s = "theeare"    print (longestVowel(s))    # This code is contributed by Chitranayal
// 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 Math.Max(res, count);    } // Driver codepublic static void Main ()    {        String s = "theeare";        Console.Write(longestVowel(s));    }} // This code is contributed by nitin mittal
<?php// PHP program to find the// longest substring of vowels.function isVowel($c){    return ($c == 'a' || $c == 'e' ||            $c == 'i' || $c == 'o' ||            $c == 'u');} function longestVowel($s){    $count = 0; $res = 0;    for ($i = 0; $i < strlen($s); $i++)    {         // Increment current count        // if s[i] is vowel        if (isVowel($s[$i]))        $count++;             else        {             // check previous value            // is greater then or not            $res = max($res, $count);             $count = 0;        }    }    return max($res, $count);} // Driver code$s = "theeare";echo longestVowel($s) ; // This code is contributed// by nitin mittal.?>
<script> // Javascript program to find the// longest substring of vowels.function isVowel(c){    return (c == 'a' || c == 'e' ||            c == 'i' || c == 'o' ||            c == 'u');} function longestVowel(str){    let count = 0, res = 0;    let s = str.split("");          for(let 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 Math.max(res, count);} // Driver codelet s = "theeare";document.write(longestVowel(s)); // This code is contributed by avanitrachhadiya2155     </script>
3
Time Complexity: O(n)
Auxiliary Space: O(1)
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nitin mittal
ukasp
prashilgupta
avanitrachhadiya2155
rishavnitro
vowel-consonant
Strings
Strings
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