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

#define MAX_STR_NUM 64
#define MAX_STR_LEN 49

char* nextLine() {
   char* result;
   char* string = malloc(sizeof(char)*(MAX_STR_LEN));
   int position = 0;
   do
   {
      string[position] = getchar();
      position++;
   } while ((position < MAX_STR_LEN) && (string[position-1] != '\n'));
   string[position-1] = '\0';
   result = malloc(sizeof(char)*(position+1));
   strcpy(result,string);
   free(string);
   return result;
}

void trimLeading(char *string) {
   int length = strlen(string);
   int i;
   for(i = 0; string[i] == ' '; i++) {}
   if(i != 0){
      for(int j = i; j < length; j++){
         string[j-i] = string[j];
         string[j] = ' ';
      }
   }
}

void trimMiddle(char *string) {
   int length = strlen(string);
   char* temp = malloc(sizeof(char)*length);
   int counter = 0;
   for(int i=0; i<length; i++){
      if(string[i] != ' '){
         temp[counter] = string[i];
         counter++;
      } else if(string[i+1] != ' ') {
         temp[counter] = string[i];
         counter++;
      }
   }
   strcpy(string,temp);
   free(temp);
}

void trimTrailing(char *string) {
   int length = strlen(string);
   if(length != 0){
      for(int i = length-1; string[i] == ' '; i--){
         string[i] = '\0';
      }
   }
}

void trim(char *string) {
   trimMiddle(string);
   trimLeading(string);
   trimTrailing(string);
}

int main(){
   char *pointers[MAX_STR_NUM];
   char *string = malloc(sizeof(char)*MAX_STR_LEN);
   int counter = 0;
   do{
      printf("Enter a string: ");
      string = nextLine();
      trim(string);
      pointers[counter] = malloc(sizeof(char)*strlen(string));
      strcpy(pointers[counter],string);
      printf("User entered \"");
      printf(pointers[counter]);
      printf("\"\n");
      counter++;
   } while(counter < MAX_STR_NUM && strlen(string) != 0);
   free(string);
   return 0;
}