Answer to Question #140041 in C for a

Question

1. Create a program that sorts the words of a string based on the first letter of each word.
2. • You may use stdio.h and string.h.
3. • Remove any trailing newline \n from your input string. • Use the insert function that we went over in class.
4. • Your input prompt should be "Enter a string: ".
5. • The output should be the sorted string on a new line. • Save your code as prob2.c.
6. Example Run

            Enter a string: this is a string
            a is string this

Answer 1

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

/* Create a program that sorts the words of a string based on the first letter of each word.
   • You may use stdio.h and string.h.
   • Remove any trailing newline \n from your input string.
   • Use the insert function that we went over in class.
   • Your input prompt should be "Enter a string: ".
   • The output should be the sorted string on a new line.
   • Save your code as prob2.c.
*/

int isAlpha(char c) {
   if (c >= 'a' && c <= 'z') return 1;
   if (c >= 'A' && c <= 'Z') return 1;
   return 0;
}

void buble_sort(char *words[], int words_count) {
 int i,j;

 for (int i = 0; i < words_count - 1; i++) {
   for (int j = (words_count - 1); j > i; j--) {
     if (*words[j - 1] > *words[j]) {
       char *temp = words[j - 1];
       words[j - 1] = words[j];
       words[j] = temp;
     }
   }
 }
}

int main(int argc, char *argv[]) {
   char buffer[256];
   char result[256];
   int len, j;
   char *words[128];
   int words_count = 0;

   // Your input prompt should be "Enter a string: "
   printf("Enter a string: ");
   fgets(buffer, 256, stdin);

   // Remove any trailing newline \n from your input string
   len = strlen(buffer);
   if (buffer[len-1] == '\n') {
       len--;
       buffer[len] = '\0';
   }

   // Sorts the words of a string based on the first letter of each word
   for(j=0; j<128; j++) words[j] = NULL;

   // First word
   if (isAlpha(buffer[0])) words[0] = buffer;

   // The rest of the words
   if (len > 1) {
      j = 1;
      words_count = 1;
   while (j < len) {
      if (isAlpha(buffer[j]) && buffer[j-1]==' ') {
         words[words_count] = buffer+j;
         words_count++;
         buffer[j-1]='\0';
      }
      j++;
   }
   printf("\n");
   }

   // Sorting
   buble_sort(words, words_count);

   // The output should be the sorted string on a new line.
   j = 0;
   result[0] = '\0';
   while (words[j] != NULL) {
       strncat(result, words[j], 256);
       strncat(result, " ", 256);
       j++;
   }
   printf("%s\n", result);

}