给定字符串中的反转元音

给定一个字符串，你的任务是只反转字符串的元音。
例子：

Input : hello
Output : holle

Input : hello world
Output : hollo werld

一个简单的解决方案是在扫描字符串时存储所有元音，并在另一个字符串迭代中以相反的顺序放置元音。

C++

// C++ program to reverse order of vowels
#include
using namespace std;
 
// utility function to check for vowel
bool isVowel(char c)
{
    return (c=='a' || c=='A' || c=='e' ||
            c=='E' || c=='i' || c=='I' ||
            c=='o' || c=='O' || c=='u' ||
            c=='U');
}
 
// Function to reverse order of vowels
string reverseVowel(string str)
{
    int j=0;
    // Storing the vowels separately
    string vowel;
    for (int i=0; str[i]!='\0'; i++)
        if (isVowel(str[i]))
            vowel[j++] = str[i];
 
    // Placing the vowels in the reverse
    // order in the string
    for (int i=0; str[i]!='\0'; i++)
        if (isVowel(str[i]))
            str[i] = vowel[--j] ;
 
    return str;
}
 
// Driver function
int main()
{
    string str = "hello world";
    cout << reverseVowel(str);
    return 0;
}

Java

// Java program to reverse order of vowels
 
class GFG {
 
// utility function to check for vowel
    static boolean isVowel(char c) {
        return (c == 'a' || c == 'A' || c == 'e'
                || c == 'E' || c == 'i' || c == 'I'
                || c == 'o' || c == 'O' || c == 'u'
                || c == 'U');
    }
 
// Function to reverse order of vowels
    static String reverseVowel(String str1) {
        int j = 0;
        // Storing the vowels separately
        char[] str = str1.toCharArray();
        String vowel = "";
        for (int i = 0; i < str.length; i++) {
            if (isVowel(str[i])) {
                j++;
                vowel += str[i];
            }
        }
 
        // Placing the vowels in the reverse
        // order in the string
        for (int i = 0; i < str.length; i++) {
            if (isVowel(str[i])) {
                str[i] = vowel.charAt(--j);
            }
        }
 
        return String.valueOf(str);
    }
 
// Driver function
    public static void main(String[] args) {
        String str = "hello world";
        System.out.println(reverseVowel(str));
    }
}
 
// This code is contributed by princiRaj1992

Python3

# Python3 program to reverse order of vowels
 
# utility function to check for vowel
def isVowel(c):
    if (c == 'a' or c == 'A' or c == 'e' or
        c == 'E' or c == 'i' or c == 'I' or
        c == 'o' or c == 'O' or c == 'u' or c == 'U'):
        return True
    return False
 
# Function to reverse order of vowels
def reverserVowel(string):
    j = 0
    vowel = [0] * len(string)
    string = list(string)
 
    # Storing the vowels separately
    for i in range(len(string)):
        if isVowel(string[i]):
            vowel[j] = string[i]
            j += 1
 
    # Placing the vowels in the reverse
    # order in the string
    for i in range(len(string)):
        if isVowel(string[i]):
            j -= 1
            string[i] = vowel[j]
 
    return ''.join(string)
 
# Driver Code
if __name__ == "__main__":
    string = "hello world"
    print(reverserVowel(string))
 
# This code is contributed by
# sanjeev2552

C#

// C# program to reverse order of vowels
using System;
 
class GFG
{
 
    // utility function to check for vowel
    static bool isVowel(char c)
    {
        return (c == 'a' || c == 'A' || c == 'e'
                || c == 'E' || c == 'i' || c == 'I'
                || c == 'o' || c == 'O' || c == 'u'
                || c == 'U');
    }
 
    // Function to reverse order of vowels
    static String reverseVowel(String str1)
    {
        int j = 0;
         
        // Storing the vowels separately
        char[] str = str1.ToCharArray();
        String vowel = "";
        for (int i = 0; i < str.Length; i++)
        {
            if (isVowel(str[i]))
            {
                j++;
                vowel += str[i];
            }
        }
 
        // Placing the vowels in the reverse
        // order in the string
        for (int i = 0; i < str.Length; i++)
        {
            if (isVowel(str[i]))
            {
                str[i] = vowel[--j];
            }
        }
 
        return String.Join("",str);
    }
 
    // Driver code
    public static void Main(String[] args)
    {
        String str = "hello world";
        Console.WriteLine(reverseVowel(str));
    }
}
 
// This code has been contributed by 29AjayKumar

Javascript

 
    // JavaScript program to reverse order of vowels
     
    // utility function to check for vowel
    function isVowel(c) {
        return (c == 'a' || c == 'A' || c == 'e'
                || c == 'E' || c == 'i' || c == 'I'
                || c == 'o' || c == 'O' || c == 'u'
                || c == 'U');
    }
   
    // Function to reverse order of vowels
    function reverseVowel(str1) {
        let j = 0;
        // Storing the vowels separately
        let str = str1.split('');
        let vowel = "";
        for (let i = 0; i < str.length; i++) {
            if (isVowel(str[i])) {
                j++;
                vowel += str[i];
            }
        }
   
        // Placing the vowels in the reverse
        // order in the string
        for (let i = 0; i < str.length; i++) {
            if (isVowel(str[i])) {
                str[i] = vowel[--j];
            }
        }
   
        return str.join("");
    }
     
    let str = "hello world";
      document.write(reverseVowel(str));
         

输出：

hollo werld

时间复杂度： O(n) 其中 n =字符串长度
辅助空格： O(v) 其中 v =字符串中元音的数量
更好的解决方案是使用两个指针分别从数组的开头和结尾扫描并操作这些指针指向的元音。

C++

// C++ program to reverse order of vowels
#include
using namespace std;
 
// utility function to check for vowel
bool isVowel(char c)
{
    return (c=='a' || c=='A' || c=='e' ||
            c=='E' || c=='i' || c=='I' ||
            c=='o' || c=='O' || c=='u' ||
            c=='U');
}
 
// Function to reverse order of vowels
string reverseVowel(string str)
{
    // Start two indexes from two corners
    // and move toward each other
    int i = 0;
    int j = str.length()-1;
    while (i < j)
    {
        if (!isVowel(str[i]))
        {
            i++;
            continue;
        }
        if (!isVowel(str[j]))
        {
            j--;
            continue;
        }
 
        // swapping
        swap(str[i], str[j]);
 
        i++;
        j--;
    }
 
    return str;
}
 
// Driver function
int main()
{
    string str = "hello world";
    cout << reverseVowel(str);
    return 0;
}

Java

// Java program to reverse order of vowels
 
class GFG {
 
// utility function to check for vowel
    static boolean isVowel(char c) {
        return (c == 'a' || c == 'A' || c == 'e'
                || c == 'E' || c == 'i' || c == 'I'
                || c == 'o' || c == 'O' || c == 'u'
                || c == 'U');
    }
 
// Function to reverse order of vowels
static String reverseVowel(String str) {
    // Start two indexes from two corners
    // and move toward each other
    int i = 0;
    int j = str.length()-1;
    char[] str1 = str.toCharArray();
    while (i < j)
    {
        if (!isVowel(str1[i]))
        {
            i++;
            continue;
        }
        if (!isVowel(str1[j]))
        {
            j--;
            continue;
        }
 
        // swapping
        char t = str1[i];
        str1[i]= str1[j];
        str1[j]= t;
         
 
        i++;
        j--;
    }
    String str2 = String.copyValueOf(str1);
    return str2;
}
 
// Driver function
    public static void main(String[] args) {
        String str = "hello world";
        System.out.println(reverseVowel(str));
    }
}

Python3

# Python3 program to reverse order of vowels
 
# utility function to check for vowel
def isVowel(c):
    return (c=='a' or c=='A' or c=='e' or
            c=='E' or c=='i' or c=='I' or
            c=='o' or c=='O' or c=='u' or
            c=='U')
 
# Function to reverse order of vowels
def reverseVowel(str):
 
    # Start two indexes from two corners
    # and move toward each other
    i = 0
    j = len(str) - 1
    while (i < j):
        if not isVowel(str[i]):
            i += 1
            continue
        if (not isVowel(str[j])):
            j -= 1
            continue
         
        # swapping
        str[i], str[j] = str[j], str[i]
        i += 1
        j -= 1
    return str
 
# Driver function
if __name__ == "__main__":
    str = "hello world"
    print(*reverseVowel(list(str)), sep = "")
 
# This code is contributed by SHUBHAMSINGH10

C＃

// C# program to reverse order of vowels
using System;
 
class GFG
{
 
    // utility function to check for vowel
    static Boolean isVowel(char c)
    {
        return (c == 'a' || c == 'A' || c == 'e'
                || c == 'E' || c == 'i' || c == 'I'
                || c == 'o' || c == 'O' || c == 'u'
                || c == 'U');
    }
 
// Function to reverse order of vowels
static String reverseVowel(String str)
{
    // Start two indexes from two corners
    // and move toward each other
    int i = 0;
    int j = str.Length-1;
    char[] str1 = str.ToCharArray();
    while (i < j)
    {
        if (!isVowel(str1[i]))
        {
            i++;
            continue;
        }
        if (!isVowel(str1[j]))
        {
            j--;
            continue;
        }
 
        // swapping
        char t = str1[i];
        str1[i]= str1[j];
        str1[j]= t;
         
 
        i++;
        j--;
    }
    String str2 = String.Join("",str1);
    return str2;
}
 
// Driver code
public static void Main(String[] args)
{
    String str = "hello world";
    Console.WriteLine(reverseVowel(str));
}
}
 
// This code is contributed by Rajput-Ji

Javascript

 
// JavaScript program to reverse order of vowels
 
// utility function to check for vowel
function isVowel(c)
{
    return (c == 'a' || c == 'A' || c == 'e'
                || c == 'E' || c == 'i' || c == 'I'
                || c == 'o' || c == 'O' || c == 'u'
                || c == 'U');
}
 
// Function to reverse order of vowels
function reverseVowel(str)
{
    // Start two indexes from two corners
    // and move toward each other
    let i = 0;
    let j = str.length-1;
    let str1 = str.split("");
    while (i < j)
    {
        if (!isVowel(str1[i]))
        {
            i++;
            continue;
        }
        if (!isVowel(str1[j]))
        {
            j--;
            continue;
        }
  
        // swapping
        let t = str1[i];
        str1[i]= str1[j];
        str1[j]= t;
          
  
        i++;
        j--;
    }
    let str2 = (str1).join("");
    return str2;
}
 
// Driver function
let str = "hello world";
document.write(reverseVowel(str));
 
 
 
// This code is contributed by rag2127
 

输出：

hollo werld