编写一个函数实现字符串中单词的逆序，其他字符保持位置不变 请用C语言实现，至少不少于三种方法

1. 方法一：使用指针和数组实现

#include <stdio.h>
#include <string.h>

void reverseWords(char *str) {
    int len = strlen(str);
    char *start = str;
    char *end = str + len - 1;
    char temp;

    // Reverse the whole string
    while (start < end) {
        temp = *start;
        *start++ = *end;
        *end-- = temp;
    }

    // Reverse each word in the string
    start = end = str;
    while (*start) {
        while (*end != ' ' && *end != '\0') {
            end++;
        }
        end--;
        while (start < end) {
            temp = *start;
            *start++ = *end;
            *end-- = temp;
        }
        start = ++end;
    }
}

int main() {
    char str[] = "Hello world, how are you?";
    printf("Original string: %s\n", str);
    reverseWords(str);
    printf("Reversed string: %s\n", str);
    return 0;
}

2. 方法二：使用 strtok 函数实现

#include <stdio.h>
#include <string.h>

void reverseWords(char *str) {
    char *token;
    char *delimiter = " ";
    char *words[100];
    int count = 0;

    // Split the string into words
    token = strtok(str, delimiter);
    while (token != NULL) {
        words[count++] = token;
        token = strtok(NULL, delimiter);
    }

    // Reverse the order of the words
    for (int i = count - 1; i >= 0; i--) {
        printf("%s ", words[i]);
    }
    printf("\n");
}

int main() {
    char str[] = "Hello world, how are you?";
    printf("Original string: %s\n", str);
    reverseWords(str);
    return 0;
}

3. 方法三：使用递归实现

#include <stdio.h>
#include <string.h>

void reverseWords(char *str, int start, int end) {
    if (start >= end) {
        return;
    }

    // Reverse the whole string
    char temp = str[start];
    str[start] = str[end];
    str[end] = temp;

    // Reverse each word in the string
    int i = start + 1;
    while (i < end && str[i] != ' ') {
        i++;
    }
    reverseWords(str, start + 1, i - 1);
    reverseWords(str, i + 1, end);
}

int main() {
    char str[] = "Hello world, how are you?";
    printf("Original string: %s\n", str);
    reverseWords(str, 0, strlen(str) - 1);
    printf("Reversed string: %s\n", str);
    return 0;
}