usaa24/cv4/a_train.c

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

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

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

void cancel_train(struct car* first) {
    struct car* current = first;
    while(first != NULL){
        current = current->next;
        free(first);
        first = current;
    }
}


struct car* clear_train(struct car* first, const char* target) {
    if (first = NULL){
        return NULL;
    }
    struct car* current = first, new_first = first;
    if (first != NULL){
        if(strcmp(first->destination, target) == 0){
            new_first = new_first->next;
            free(first);
            first = new_first;
        }
    }

    while (first->next != NULL) {
        current = first->next;
        if (strcmp(current->destination, target) == 0) {
            first->next = current->next;
            free(current);
        } else {
            first = current;
        }
    }
    return new_first;
}