Modify the string by swapping continuous vowels or consonants

Given a string str. The task is to modify the string by swapping two adjacent characters if both of them are vowels or both of them are consonants.

Examples:

Input: str = “geeksforgeeks” 
Output: geesfkogreesk 
The alphabets ‘e’ and ‘e’ in geeksforgeeks are vowels so they are swapped so the string becomes geeksforgeeks. 
The alphabets ‘k’ and ‘s’ in geeksforgeeks are consonants so they are swapped so the string becomes geeskforgeeks. 
The alphabets ‘k’ and ‘f’ in geeskforgeeks are consonants so they are swapped so the string becomes geesfkorgeeks. 
The alphabets ‘r’ and ‘g’ in geesfkorgeeks are consonants so they are swapped so the string becomes geeskfogreeks. 
The alphabets ‘e’ and ‘e’ in geeskfogreeks are vowels so they are swapped so the string becomes geeskfogreeks. 
The alphabets ‘k’ and ‘s’ in geeskfogreeks are vowels so they are swapped so the string becomes geeskfogreesk. 

Input:str = “gefeg” 
Output: gefeg 
No continuous vowels or consonants. 

Approach:

• Traverse through the characters in the string.
• Consider the current character and the next character.
• If both the characters are consonants or both the characters are vowels.
• Then swap the characters.
• Else continue the process till the end of the string.

Below is the implementation of the above approach: 

C++

// C++ implementation of the above approach
#include <bits/stdc++.h>
using namespace std;

// Function to check if a character is a vowel
bool isVowel(char c)
{
    c = tolower(c);
    if (c == 'a' || c == 'e' || c == 'i'
                 || c == 'o' || c == 'u')
        return true;
    return false;
}

// Function to swap two consecutively
// repeated vowels or consonants
string swapRepeated(string str)
{
    // Traverse through the length of the string
    for (int i = 0; i < str.length() - 1; i++) {

        // Check if the two consecutive characters
        // are vowels or consonants
        if ((isVowel(str[i]) && isVowel(str[i + 1]))
            || (!isVowel(str[i]) && !isVowel(str[i + 1])))

            // swap the two characters
            swap(str[i], str[i + 1]);
    }

    return str;
}

// Driver code
int main()
{
    string str = "geeksforgeeks";

    cout << swapRepeated(str);
    return 0;
}

Java

// Java implementation of the above approach
class GFG
{

    // Function to check if a
    // character is a 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 swap two consecutively
    // repeated vowels or consonants
    static String swapRepeated(char str[])
    {

        // Traverse through the
        // length of the string
        for (int i = 0; i < str.length - 1; i++)
        {
            char c = 0;

            // Check if the two consecutive characters
            // are vowels or consonants
            if ((isVowel(str[i]) && isVowel(str[i + 1]))
                || (!isVowel(str[i]) && !isVowel(str[i + 1])))
            {

                // swap the two characters
                c = str[i];
                str[i] = str[i + 1];
                str[i + 1] = c;
            }
        }
        return String.valueOf(str);
    }

    // Driver code
    public static void main(String[] args)
    {
        String str = "geeksforgeeks";
        System.out.println(swapRepeated(str.toCharArray()));
    }
}

// This code is contributed by 29AjayKumar

Python 3

# Python3 implementation of the above approach

# Function to check if a character is a vowel
def 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 swap two consecutively
# repeated vowels or consonants
def swapRepeated(string) :

    # Traverse through the length of the string
    for i in range(len(string) - 1) :

        # Check if the two consecutive characters
        # are vowels or consonants
        if ((isVowel(string[i]) and isVowel(string[i + 1])) or
        (not(isVowel(string[i])) and not(isVowel(string[i + 1])))) :

            # swap the two characters
            (string[i],
             string[i + 1]) = (string[i + 1],
                               string[i]);

    string = "".join(string)
    return string;

# Driver code
if __name__ == "__main__" :

    string = "geeksforgeeks";

    print(swapRepeated(list(string)));

# This code is contributed by Ryuga

C#

// C# implementation of the above approach
using System;

class GFG
{

    // Function to check if a
    // character is a 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 swap two consecutively
    // repeated vowels or consonants
    static String swapRepeated(char []str)
    {

        // Traverse through the
        // length of the string
        for (int i = 0; i < str.Length - 1; i++)
        {
            char c = (char)0;

            // Check if the two consecutive characters
            // are vowels or consonants
            if ((isVowel(str[i]) && isVowel(str[i + 1]))
                || (!isVowel(str[i]) && !isVowel(str[i + 1])))
            {

                // swap the two characters
                c = str[i];
                str[i] = str[i + 1];
                str[i + 1] = c;
            }
        }
        return String.Join("",str);
    }

    // Driver code
    public static void Main(String[] args)
    {
        String str = "geeksforgeeks";
        Console.WriteLine(swapRepeated(str.ToCharArray()));
    }
}

/* This code contributed by PrinciRaj1992 */

PHP

<?php

// PHP implementation of the above approach

// Function to check if a character is a vowel
function isVowel($c)
{
    $c = strtolower($c);
    if ($c == 'a' || $c == 'e' || $c == 'i'
                || $c == 'o' || $c == 'u')
        return true;
    return false;
}

// Function to swap two consecutively
// repeated vowels or consonants
function swapRepeated($str)
{
    // Traverse through the length of the string
    for ($i = 0; $i < strlen($str) - 1; $i++) {

        // Check if the two consecutive characters
        // are vowels or consonants
        if ((isVowel($str[$i]) && isVowel($str[$i + 1]))
            || (!isVowel($str[$i]) && !isVowel($str[$i + 1])))
        {
            // swap the two characters
            $t = $str[$i];
            $str[$i]= $str[$i + 1];
            $str[$i+1] = $t;
        }
    }

    return $str;
}

    // Driver code

    $str = "geeksforgeeks";

    echo swapRepeated($str);
    return 0;

// This code is contributed by ChitraNayal
?>

Javascript

<script>
      // JavaScript implementation of the above approach
      // Function to check if a
      // character is a vowel
      function isVowel(c) {
        c = c.toLowerCase();
        if (c === "a" || c === "e" || c === "i" || c === "o" || c === "u") {
          return true;
        }
        return false;
      }

      // Function to swap two consecutively
      // repeated vowels or consonants
      function swapRepeated(str) {
        // Traverse through the
        // length of the string
        for (var i = 0; i < str.length - 1; i++) {
          // Check if the two consecutive characters
          // are vowels or consonants
          if (
            (isVowel(str[i]) && isVowel(str[i + 1])) ||
            (!isVowel(str[i]) && !isVowel(str[i + 1]))
          ) {
            // swap the two characters
            var c = str[i];
            str[i] = str[i + 1];
            str[i + 1] = c;
          }
        }
        return str.join("");
      }

      // Driver code
      var str = "geeksforgeeks";
      document.write(swapRepeated(str.split("")));
    </script>

Output

geesfkogreesk

Complexity Analysis:

• Time Complexity: O(N) for traversing the given string str.
• Auxiliary Space: O(1) as constant space is used.