How do you reverse the word order in a sentence?-CodePudding

The task was to reverse the order of words in the sentence I was able to reverse the order of the words, but the problem is that the order of the letters in the word also changes

For example: cats and dogs

The miracle in my plan:tac dna sgod

The desired output: dogs and cats

How can I fix the code to work correctly?

this is my code:

void revSent(char str[]) {
    int i;
    int n = strlen(str);
    char letter;

    for (i = 0; i < n / 2; i  ) {
        letter = str[i];
        str[i] = str[strlen(str) - i - 1];

        str[strlen(str) - i - 1]=letter ;
    
    }
}

CodePudding user response：

You could split your sentence with the whitespace and then you can reorder the resulting array in reverse.

CodePudding user response：

The usual approach is to reverse the whole string and then to reverse each word in the string separately.

To extract words in a string you can use standard string functions strspn and strcspn.

Here is a demonstration program

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

void reverse_n( char *s, size_t n )
{
    for (size_t i = 0; i < n / 2; i  )
    {
        char c = s[i];
        s[i] = s[n - i - 1];
        s[n - i - 1] = c;
    }
}

char *revSent( char *s )
{
    const char *blank = " \t";

    reverse_n( s, strlen( s ) );

    for (char *p = s; *p; )
    {
        p  = strspn( p, blank );

        if (*p)
        {
            size_t n = strcspn( p, blank );
            reverse_n( p, n );
            p  = n;
        }
    }

    return s;
}

int main( void )
{
    char s[] = "cats and dogs";

    puts( s );
    puts( revSent( s ) );
}

The program output is

cats and dogs
dogs and cats