C language. work with text

hello, I just recently started learning C language. Please do not swear at me))

i want to make a program
I enter text from the keyboard into the console and I want the program to swap the first and last letter of each word and count how many words are in the sentence.
I found a program on the Internet that swaps letters and altered it a little
how can i fix it?
I did it but he only counts the words

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


char * swap(const char * str);

int main(void)
{
char s[200];
int count = 0, i;
printf("Enter the string:\n");
scanf("%[^\n]s", s);
for (i = 0;s != '\0';i++)

{
if (s == ' ' && s[i+1] != ' ')
count++;
}
printf("words: %d\n", count + 1);
}

char * swap(char * s)
{
const size_t length = strlen(s);
char * ch = malloc(length + 1);

strncat(ch, s, length);
ch[length] = '\0';

char * k = ch;

while (k != NULL)
{
char * last = strchr(k, ' ');

if (last != NULL)
{
char t = *k;
*k = *(last - 1);
*(last - 1) = t;
k = last + 1;
}
else
{
char t = *(k);
*k = *(ch + length - 1);
*(ch + length - 1) = t;
k = NULL;
}
}

return ch;
}