根据字数反转字符串

给定一个包含多个单词的字符串。如果字符串中的单词数是偶数，则反转其偶数位置的单词，否则反转其奇数位置，将反转的单词推入新字符串的开头并按顺序附加剩余的单词。

例子：

Input:  Ashish Yadav Abhishek Rajput Sunil Pundir
Output: ridnuP tupjaR vadaY Ashish Abhishek Sunil

Input:  Ashish Yadav Abhishek Rajput Sunil Pundir Prem
Output: merP linuS kehsihbA hsihsA Yadav Rajput Pundir 

方法：如果单词数是偶数，则偶数位置的单词先出现并反转该特定单词，如果单词数为奇数则奇数位置的单词先出现并反转该特定单词，然后其余单词按顺序附加.例如

Ashish Yadav Abhishek Rajput Sunil Pundir. 
In the above string, the number of words is even then “Yadav Rajput Pundir” comes at the even position and then the final output will be: 
ridnuP tupjaR vadaY Ashish Abhishek Sunil 

C++

// C++ program to reverse string
// according to the number of words
#include 
using namespace std;
 
// Reverse the letters of the word
void reverse(char str[], int start, int end)
{
 
    // Temporary variable to store character
    char temp;
    while (start <= end)
    {
        // Swapping the first and last character
        temp = str[start];
        str[start] = str[end];
        str[end] = temp;
        start++;
        end--;
    }
}
 
// This function forms the required string
void reverseletter(char str[], int start, int end)
{
    int wstart, wend;
    for (wstart = wend = start; wend < end; wend++)
    {
        if (str[wend] == ' ')
            continue;
             
        // Checking the number of words
        // present in string to reverse
        while (str[wend] != ' ' && wend <= end)
            wend++;
        wend--;
         
        // Reverse the letter
        // of the words
        reverse(str, wstart, wend);
    }
}
 
// Driver Code
int main()
{
    char str[1000] = "Ashish Yadav Abhishek Rajput Sunil Pundir";
    reverseletter(str, 0, strlen(str) - 1);
    cout << str;
    return 0;
}
 
// This code is contributed by SHUBHAMSINGH10

C

// C program to reverse string
// according to the number of words
#include
#include
 
// Reverse the letters of the word
void reverse(char str[], int start, int end) {
 
    // Temporary variable to store character
    char temp;
    while (start <= end)
    {
        // Swapping the first and last character
        temp = str[start];
        str[start] = str[end];
        str[end] = temp;
        start++;
        end--;
    }
}
 
// This function forms the required string
void reverseletter(char str[], int start, int end) {
             
    int wstart, wend;
    for (wstart = wend = start; wend < end; wend++) {
                     
        if (str[wend] == ' ')
            continue;
             
        // Checking the number of words
        // present in string to reverse
        while (str[wend] != ' ' && wend <= end)
            wend++;
        wend--;
         
        //Reverse the letter
        //of the words
        reverse(str, wstart, wend);
    }
}
 
// Driver Code
int main()
{
    char str[1000] = "Ashish Yadav Abhishek Rajput Sunil Pundir";
    reverseletter(str, 0, strlen(str)-1);
    printf("%s", str);
    return 0;
}

Java

// Java program to reverse string
// according to the number of words
class GFG
{
 
    // Reverse the letters of the word
    static void reverse(char str[],
                       int start, int end)
    {
 
        // Temporary variable to store character
        char temp;
        while (start <= end)
        {
            // Swapping the first and last character
            temp = str[start];
            str[start] = str[end];
            str[end] = temp;
            start++;
            end--;
        }
    }
 
    // This function forms the required string
    static void reverseletter(char str[],
                            int start, int end)
    {
 
        int wstart, wend;
        for (wstart = wend = start; wend < end; wend++)
        {
 
            if (str[wend] == ' ')
            {
                continue;
            }
 
            // Checking the number of words
            // present in string to reverse
            while (wend <= end && str[wend] != ' ')
            {
                wend++;
            }
            wend--;
 
            // Reverse the letter
            // of the words
            reverse(str, wstart, wend);
        }
    }
 
    // Driver Code
    public static void main(String[] args)
    {
        char str[] = "Ashish Yadav Abhishek Rajput Sunil Pundir".toCharArray();
        reverseletter(str, 0, str.length - 1);
        System.out.printf("%s", String.valueOf(str));
    }
}
 
// This code contributed by Rajput-Ji

Python3

# Python3 program to reverse string
# according to the number of words
 
# Reverse the letters of the word
def reverse(string, start, end):
 
    # Temporary variable to store character
    temp = ''
    while start <= end:
 
        # Swapping the first and last character
        temp = string[start]
        string[start] = string[end]
        string[end] = temp
        start += 1
        end -= 1
 
# This function forms the required string
def reverseletter(string, start, end):
    wstart, wend = start, start
 
    while wend < end:
        if string[wend] == " ":
            wend += 1
            continue
 
        # Checking the number of words
        # present in string to reverse
        while wend <= end and string[wend] != " ":
            wend += 1
        wend -= 1
 
        # Reverse the letter
        # of the words
        reverse(string, wstart, wend)
        wend += 1
 
# Driver Code
if __name__ == "__main__":
    string = "Ashish Yadav Abhishek Rajput Sunil Pundir"
    string = list(string)
    reverseletter(string, 0, len(string) - 1)
    print(''.join(string))
 
# This code is contributed by
# sanjeev2552

C#

// C# program to reverse string
// according to the number of words
using System;
     
class GFG
{
  
    // Reverse the letters of the word
    static void reverse(char []str,
                       int start, int end)
    {
  
        // Temporary variable to store character
        char temp;
        while (start <= end)
        {
            // Swapping the first and last character
            temp = str[start];
            str[start] = str[end];
            str[end] = temp;
            start++;
            end--;
        }
    }
  
    // This function forms the required string
    static void reverseletter(char []str,
                            int start, int end)
    {
  
        int wstart, wend;
        for (wstart = wend = start; wend < end; wend++)
        {
  
            if (str[wend] == ' ')
            {
                continue;
            }
  
            // Checking the number of words
            // present in string to reverse
            while (wend <= end && str[wend] != ' ')
            {
                wend++;
            }
            wend--;
  
            // Reverse the letter
            // of the words
            reverse(str, wstart, wend);
        }
    }
  
    // Driver Code
    public static void Main(String[] args)
    {
        char []str = "Ashish Yadav Abhishek Rajput Sunil Pundir".ToCharArray();
        reverseletter(str, 0, str.Length - 1);
        Console.Write("{0}", String.Join("",str));
    }
}
 
// This code has been contributed by 29AjayKumar

Javascript

// Javascript program to reverse string
// according to the number of words
 
// Reverse the letters of the word
function reverse(str,start,end)
{
    // Temporary variable to store character
        let temp;
        while (start <= end)
        {
            // Swapping the first and last character
            temp = str[start];
            str[start] = str[end];
            str[end] = temp;
            start++;
            end--;
        }
}
 
// This function forms the required string
function reverseletter(str,start,end)
{
    let wstart, wend;
        for (wstart = wend = start; wend < end; wend++)
        {
   
            if (str[wend] == ' ')
            {
                continue;
            }
   
            // Checking the number of words
            // present in string to reverse
            while (wend <= end && str[wend] != ' ')
            {
                wend++;
            }
            wend--;
   
            // Reverse the letter
            // of the words
            reverse(str, wstart, wend);
        }
}
 
 // Driver Code
let str= "Ashish Yadav Abhishek Rajput Sunil Pundir".split("");
reverseletter(str, 0, str.length - 1);
document.write((str).join(""));
 
// This code is contributed by rag2127

输出：

ridnuP tupjaR vadaY Ashish Abhishek Sunil