#include "a_train.h"
#include <stdio.h>

struct car* add_car(struct car* first,const char* target) {
    struct car *newCar = calloc(1,sizeof(struct car));
	strcpy(newCar->value,target);
	
	if(first==NULL){
		first = newCar;
	}else{
		struct car* this = first;
		while(this->next!=NULL){
			this = this->next;
		}
		this->next = newCar;
	}
	return first;
}

void print_train(struct car* first) {
	for(struct car* this = first;this!=NULL;this = this->next){
		printf("%s\n",this->value);
	}
}

void cancel_train(struct car* first){
	if(first==NULL){
		return;
	}
	cancel_train(first->next);
	free(first);
}


struct car* clear_train(struct car* first, const char* target) {
	
	struct car *previous = NULL; 
	for(struct car *this = first;this!=NULL;this=this->next){
		if(strcmp(this->value,target)==0){
			if(previous==NULL){
				first = first->next;
				free(this);
				break;
			}else{
				previous->next = this->next;
				free(this);
				break;
			}
			
		}
		previous = this;
	}
	return first;
}