Why fgets() doesn't read after the first element? - c

Question

I am trying to do this programming project in the book i study:
Write a program that sorts a series of words entered by the user:
Enter word: foo
Enter word: bar
Enter word: baz
Enter word: quux
Enter word:
In sorted order: bar baz foo quux
Assume that each word is no more than 20 characters long. Stop reading when the user enters an empty word (i.e., presses Enter without entering a word). Store each word in a dynamically sllocated string, using an array of pointers to keep track of the strings.
After all words have been read, sort the array (using any sorting technique) and then use a loop to print the words in sorted order.
That is what i am trying:
#include <stdio.h>
#include <string.h>
#define MAX_LENGTH 20
int compare ( const void * p, const void * q);
int main (void){
int n;
printf("How many words do you want to write");
scanf("%d", &n);
fflush(stdin);
char * word[n];
for( int i = 0; i < n; i++){
fprintf(stdout , "Waiting for the word:");
if(fgets(word[i] , MAX_LENGTH +1 , stdin) == "\n")
break;
}
qsort((void *)word,n,sizeof(int),compare);
printf("Ordered list is:\n\n");
for( int i = 0; i < n; i++){
fprintf(stdout , "\t %s", word[i]);
}
}
int compare (const void * p, const void * q){
return strcmp( * (char**) p , * (char **) q);
}
Edit : question with italic is solved thanks to fellow coders here. My new issue is i can't read past the first element of array. And program closes itself.
C:\Users\Lenovo\Desktop\ogrenme\ch17>sorting
How many words do you want to write4
Waiting for the word:asd
C:\Users\Lenovo\Desktop\ogrenme\ch17>
And there is one single annoying error that keeps me prevented from completing the exercise and "chill" with rest of this challenging book:
sorting.c:20:5: warning: implicit declaration of function 'qsort' [-Wimplicit-function-declaration]
qsort((void *)word,n,sizeof(int),compare);

Answer 1

I did a small trial (definitely the code could be optimized)
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main (void) {
int n = 0;
char **string_list;
char *tmp;
//allocate memory for the first element
string_list = (char**)malloc(sizeof(char*)*1);
//infinite loop
while ( 1 ) {
//allocate size of each element to a max of 20 chars
string_list[n] = (char*)malloc(sizeof(char)*20);
printf("Enter word : ");
fgets (string_list[n], 20, stdin);
//remove trailing return carriage
string_list[n][strlen(string_list[n]) - 1] = '\0';
//break the loop here if user enters empty string
if (strlen(string_list[n]) < 1) {
break;
}
//add counter
n++;
//add memory to contain another element
string_list = realloc(string_list, sizeof(char*)*(n+1));
}
printf("\n\nInitial List is:\n");
for (int i=0 ; i<n-1 ; i++) {
printf("%s - ", string_list[i]);
}
printf("%s\n\n", string_list[n-1]);
//sorting the list
for (int i=0; i<n; i++) {
for (int j=0; j<n; j++) {
if (strcmp(string_list[i], string_list[j]) < 0) {
tmp = string_list[i];
string_list[i] = string_list[j];
string_list[j] = tmp;
}
}
}
printf("Sorted List is:\n");
for (int i=0 ; i<n-1 ; i++) {
printf("%s - ", string_list[i], strlen(string_list[i]));
}
printf("%s\n\n", string_list[n-1], strlen(string_list[n-1]));
}
output
$ ./sort
Enter word : foo
Enter word : bar
Enter word : baz
Enter word : quux
Enter word :
Initial List is:
foo - bar - baz - quux
Sorted List is:
bar - baz - foo - quux