reverse_it.c

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

char * reverseWords(const char *text);
char * reverseWord(char *word);

int main () {
  char *text = "Hello World";
  char *result = reverseWords(text);
  printf("%s == %s\n", result, "olleH dlroW");
  printf("%d\n", (result == "olleH dlroW"));
  return 0;
}

char *
reverseWords (const char *text) {
  int i, j;
  size_t len = strlen(text);
  size_t text_size = len * sizeof(char);
  char *output;
  char *temp_word;
  char temp_char;
  
  output = (char *) malloc (text_size + 1);

  for(i = 0; i < len; i++) {

    if (text[i] == ' ') {
      output[i] = ' ';
    }
    if (text[i] == '\0') {
      break;
    }
    temp_word = (char *) malloc (text_size + 1);
    j = 0;
    while((text[i + j] != ' ') && (text[i + j] != '\0')) {
      temp_char = (char) text[i+j];
      strcat(temp_word, &temp_char);
      j++;
    }
    strcat(output, reverseWord(temp_word));
    if (text[i+j] == ' ')
      strcat(output, " ");
    free(temp_word);
    i += j;
  }

  return strstr(output, "\0");
  // return output;
}

char *
reverseWord (char *word) {
  int i, j;
  size_t len = strlen(word);
  char *output;

  output = (char *) malloc (len + 1);

  j = 0;
  for(i = (len - 1); i >= 0; i--) {
    output[j++] = word[i];
  }

  return output;
}