usaa20/cv5/a_train.c

#include <stdio.h>

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

#include "a_train.h"

struct car* add_car(struct car* first,const char* target) {
    struct car* newcar = calloc(1, sizeof(struct car));
    if(target == NULL){
        return;
    }
    strcpy(newcar->value, target);
   
    if(first == NULL){
        return newcar;
    }
    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);
    }
    /*struct car* this = first;
    if(first == NULL){
        exit(0);   
    }
    else{  
      while(this != NULL){
            printf("%s\n", this->value);
            this = this->next;
        }
    }*/
}

void cancel_train(struct car* first) {   
    if(first == NULL){
        return;
    }
    else if(first->value != NULL){
       struct car* help = first->next;
       free(first);
       //first->next = NULL;
       cancel_train(help);
       //first->next = NULL;
    }
    else if(first->next == NULL){
        free(first);
        cancel_train(first->next);
    }

}



struct car* clear_train(struct car* first, const char* target) {
    struct car* this = first;
    while(this != NULL){
        if(this->value == target){
            return NULL;    
        }
        this = this->next;
        
    }
    return first;
}