Find substrings that contain all vowels

We have been given a string in lowercase alphabets. We need to print substrings that contain all the vowels at least one time and there are no consonants (non-vowel characters) present in the substrings.

Examples:

Input : str = aeoibddaeoiud
Output : aeoiu

Input : str = aeoibsddaeiouudb
Output : aeiou, aeiouu

Reference:- Samsung Interview Questions.

We use a hashing based technique and start traversing the string from the start. For every character, we consider all substrings starting from it. If we encounter a consonant, we move to the next starting character. Else, we insert the current character in a hash. If all vowels are included, we print the current substring. 

Implementation:

C++

// CPP program to find all substring that
// contain all vowels
#include <bits/stdc++.h>

using namespace std;

// Returns true if x is vowel.
bool isVowel(char x)
{
    // Function to check whether a character is
    // vowel or not
    return (x == 'a' || x == 'e' || x == 'i' ||
                        x == 'o' || x == 'u');
}

void FindSubstring(string str)
{
    set<char> hash; // To store vowels

    // Outer loop picks starting character and
    // inner loop picks ending character.
    int n = str.length();
    for (int i = 0; i < n; i++) {
       for (int j = i; j < n; j++) {

            // If current character is not vowel,
            // then no more result substrings
            // possible starting from str[i].
            if (isVowel(str[j]) == false)
              break;

            // If vowel, then we insert it in hash
            hash.insert(str[j]);

            // If all vowels are present in current
            // substring
            if (hash.size() == 5)
                cout << str.substr(i, j-i+1) << " ";
        }

        hash.clear();
    }
}

// Driver code
int main()
{
    string str = "aeoibsddaeiouudb";
    FindSubstring(str);
    return 0;
}

Java

// Java program to find all substring that
// contain all vowels
import java.util.HashSet;

public class GFG {

    // Returns true if x is vowel.
    static boolean isVowel(char x) {
        // Function to check whether a character is
        // vowel or not
        return (x == 'a' || x == 'e' || x == 'i'
                || x == 'o' || x == 'u');
    }

    static void findSubstring(String str) {
        HashSet<Character> hash = new HashSet<Character>();
            // To store vowels

        // Outer loop picks starting character and
        // inner loop picks ending character.
        int n = str.length();
        for (int i = 0; i < n; i++) {
            for (int j = i; j < n; j++) {

                // If current character is not vowel,
                // then no more result substrings
                // possible starting from str[i].
                if (isVowel(str.charAt(j)) == false)
                    break;

                // If vowel, then we insert it in hash
                hash.add(str.charAt(j));

                // If all vowels are present in current
                // substring
                if (hash.size() == 5)
                    System.out.print(str.substring(i, j + 1) + " ");
            }
            hash.clear();
        }
    }

    // Driver code
    public static void main(String[] args) {
        String str = "aeoibsddaeiouudb";
        findSubstring(str);
    }
}

Python3

# Python3 program to find all substring that
# contain all vowels

# Returns true if x is vowel.
def isVowel(x):

    # Function to check whether a character is
    # vowel or not
    if (x == 'a' or x == 'e' or x == 'i' or
        x == 'o' or x == 'u'):
        return True
    return False

def FindSubstring(str1):

    # To store vowels

    # Outer loop picks starting character and
    # inner loop picks ending character.
    n = len(str1)
    for i in range(n):
        hash = dict()
        for j in range(i, n):

            # If current character is not vowel,
            # then no more result substrings
            # possible starting from str1[i].
            if (isVowel(str1[j]) == False):
                break

            # If vowel, then we insert it in hash
            hash[str1[j]] = 1

            # If all vowels are present in current
            # substring
            if (len(hash) == 5):
                print(str1[i:j + 1], end = " ")

# Driver code
str1 = "aeoibsddaeiouudb"
FindSubstring(str1)

# This code is contributed by Mohit Kumar

C#

// C# program to find all substring that
// contain all vowels
using System;
using System.Collections.Generic;

public class GFG
{

// Returns true if x is vowel.
public static bool isVowel(char x)
{
    // Function to check whether a
    // character is vowel or not
    return (x == 'a' || x == 'e' ||
            x == 'i' || x == 'o' || x == 'u');
}

public static void findSubstring(string str)
{
    HashSet<char> hash = new HashSet<char>();

    // To store vowels
    // Outer loop picks starting character and
    // inner loop picks ending character.
    int n = str.Length;
    for (int i = 0; i < n; i++)
    {
        for (int j = i; j < n; j++)
        {

            // If current character is not vowel,
            // then no more result substrings
            // possible starting from str[i].
            if (isVowel(str[j]) == false)
            {
                break;
            }

            // If vowel, then we insert it in hash
            hash.Add(str[j]);

            // If all vowels are present in current
            // substring
            if (hash.Count == 5)
            {
                Console.Write(str.Substring(i,
                             (j + 1) - i) + " ");
            }
        }
        hash.Clear();
    }
}

// Driver code
public static void Main(string[] args)
{
    string str = "aeoibsddaeiouudb";
    findSubstring(str);
}
}

// This code is contributed by Shrikant13

Javascript

<script>
// Javascript program to find all substring that
// contain all vowels

    // Returns true if x is vowel.
    function isVowel(x)
    {
        // Function to check whether a character is
        // vowel or not
        return (x == 'a' || x == 'e' || x == 'i'
                || x == 'o' || x == 'u');
    }

    function findSubstring(str)
    {
        let hash = new Set();
            // To store vowels

        // Outer loop picks starting character and
        // inner loop picks ending character.
        let n = str.length;
        for (let i = 0; i < n; i++) {
            for (let j = i; j < n; j++) {

                // If current character is not vowel,
                // then no more result substrings
                // possible starting from str[i].
                if (isVowel(str[j]) == false)
                    break;

                // If vowel, then we insert it in hash
                hash.add(str[j]);

                // If all vowels are present in current
                // substring
                if (hash.size == 5)
                    document.write(str.substring(i, j + 1) + " ");
            }
            hash.clear();
        }
    }

    // Driver code
    let str = "aeoibsddaeiouudb";
    findSubstring(str);


// This code is contributed by patel2127
</script>

Output

aeiou aeiouu 

Time Complexity : O(n²)
Auxiliary Space: O(1)

Sliding Window Approach -:

Algorithm -:

1. Create a HashSet hash to store vowels.
2. Initialize a variable start to 0.
3. Traverse the string from left to right using a for loop:
    a. If the current character is a vowel, add it to the hash.
    b. If the size of the hash is 5 (all vowels are present in the current substring), print the substring from start to i+1.
    c. If the current character is not a vowel, update the start to i+1 and clear the hash.

Implementation:

C++

// C++ program to find all substring that
// contain all vowels
#include<bits/stdc++.h>

using namespace std;

// Returns true if x is vowel.
bool isVowel(char x)
{
    // Function to check whether a character is
    // vowel or not
    return (x == 'a' || x == 'e' || x == 'i' ||
                        x == 'o' || x == 'u');
}

// Function to FindSubstrings of string
void FindSubstring(string str)
{
    set<char> hash;  // To store vowels

    int start = 0;
    for (int i=0; i<str.length(); i++)
    {
        // If current character is vowel then
        // insert into hash ,
        if (isVowel(str[i]) == true)
        {
            hash.insert(str[i]);

            // If all vowels are present in current
            // substring
            if (hash.size()==5)
                cout << str.substr(start, i-start+1)
                     << " ";
        }
        else
        {
            start = i+1;
            hash.clear();
        }
    }
}

// Driver Code
int main()
{
    string str = "aeoibsddaeiouudb";
    FindSubstring(str);
    return 0;
}

Java

// Java program to find all substring that
// contain all vowels
import java.util.HashSet;

public class GFG {

    // Returns true if x is vowel.
    static boolean isVowel(char x) {
        // Function to check whether a character is
        // vowel or not
        return (x == 'a' || x == 'e' || x == 'i'
                || x == 'o' || x == 'u');
    }

    // Function to FindSubstrings of string
    static void findSubstring(String str) {
        HashSet<Character> hash = new HashSet<Character>();
        // To store vowels

        int start = 0;
        for (int i = 0; i < str.length(); i++) {
            // If current character is vowel then
            // insert into hash ,
            if (isVowel(str.charAt(i)) == true) {
                hash.add(str.charAt(i));

                // If all vowels are present in current
                // substring
                if (hash.size() == 5)
                    System.out.print(str.substring(start, i + 1) + " ");
            } else {
                start = i + 1;
                hash.clear();
            }
        }
    }

    // Driver Code
    public static void main(String[] args) {
        String str = "aeoibsddaeiouudb";
        findSubstring(str);
    }

}

Python3

# Python3 program to find all substring
# that contain all vowels

# Returns true if x is vowel.
def isVowel(x):

    # Function to check whether
    # a character is vowel or not
    return (x == 'a' or x == 'e' or
            x == 'i' or x == 'o' or
            x == 'u');

# Function to FindSubstrings of string
def FindSubstring(str):

    hash = set(); # To store vowels

    start = 0;
    for i in range(len(str)):

        # If current character is vowel
        # then insert into hash
        if (isVowel(str[i]) == True):
            hash.add(str[i]);

            # If all vowels are present
            # in current substring
            if (len(hash) == 5):
                print(str[start : i + 1],
                              end = " ");
        else:
            start = i + 1;
            hash.clear();

# Driver Code
str = "aeoibsddaeiouudb";
FindSubstring(str);

# This code is contributed by 29AjayKumar

C#

using System;
using System.Collections.Generic;

// c# program to find all substring that
// contain all vowels

public class GFG
{

    // Returns true if x is vowel.
    public static bool isVowel(char x)
    {
        // Function to check whether a character is
        // vowel or not
        return (x == 'a' || x == 'e' || x == 'i' || x == 'o' || x == 'u');
    }

    // Function to FindSubstrings of string
    public static void findSubstring(string str)
    {
        HashSet<char> hash = new HashSet<char>();
        // To store vowels

        int start = 0;
        for (int i = 0; i < str.Length; i++)
        {
            // If current character is vowel then
            // insert into hash ,
            if (isVowel(str[i]) == true)
            {
                hash.Add(str[i]);

                // If all vowels are present in current
                // substring
                if (hash.Count == 5)
                {
                    Console.Write(str.Substring(start, (i + 1) - start) + " ");
                }
            }
            else
            {
                start = i + 1;
                hash.Clear();
            }
        }
    }

    // Driver Code
    public static void Main(string[] args)
    {
        string str = "aeoibsddaeiouudb";
        findSubstring(str);
    }

}

// This code is contributed by Shrikant13

Javascript

<script>

// Javascript program to find all substring that
// contain all vowels

// Returns true if x is vowel.
function isVowel(x)
{

    // Function to check whether a character is
    // vowel or not
    return (x == 'a' || x == 'e' || x == 'i' ||
            x == 'o' || x == 'u');
}

// Function to FindSubstrings of string
function findSubstring(str)
{
    let hash = new Set();

    // To store vowels
    let start = 0;
    for(let i = 0; i < str.length; i++)
    {

        // If current character is vowel then
        // insert into hash ,
        if (isVowel(str[i]) == true)
        {
            hash.add(str[i]);

            // If all vowels are present in current
            // substring
            if (hash.size == 5)
                document.write(
                    str.substring(start, i + 1) + " ");
        }
        else
        {
            start = i + 1;
            hash.clear();
        }
    }
}

// Driver Code
let str = "aeoibsddaeiouudb";
findSubstring(str);

// This code is contributed by unknown2108

</script>

Output

aeiou aeiouu 

Time Complexity: O(n)
Auxiliary Space: O(1), the algorithm uses a HashSet to store the vowels, but the size of the HashSet is always 5 regardless of the length of the input string so it use constant space

Thanks to Kriti Shukla for suggesting this optimized solution.
This article is contributed by Ashish Madaan. If you like GeeksforGeeks and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to review-team@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.