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

#define USAGE "Commands are a single character followed optionally by a number. The valid commands are:\n\t- a <num> (add a number to the list)\n\t- p (print the list)\n\t- r <num> (remove value <num> from the list if present)\n\t- q (quit)"





list * create_list(){
  
}


list * add_value(list * l, int num){
  
}


list * remove_value(list * l, int num){
  
}

void print(list * l){
  
}



int main(int argc, char * argv[]){
  int done = 0;
  char input[32];
  char cmd;
  int data;
  int count;
  list * l = create_list();

  printf("%s\n", USAGE);
  
  while (! done){
	printf("Enter a command: ");
	if (fgets(input, 32, stdin) == NULL){
	  printf("%s\n", USAGE);
	}else{
	  count = sscanf(input,"%c %d\n", &cmd, &data);

	  switch (cmd){
	  case 'a':
		if (count != 2){
		  printf("a should be followed by a number to add\n");
		}else{
		  l = add_value(l, data);
		}
		break;
	  case 'r':
		if (count != 2){
		  printf("r should be followed by a number to remove\n");
		}else{
		  l = remove_value(l, data);
		}
		break;
	  case 'p':
		print(l);
		break;
	  case 'q':
		done = 1;
		break;
	  default:
		printf("%s\n", USAGE);   
	  }
	}
  
  }
  return 0;
}