usaa23/cv4/a_train.c

68 lines
1.6 KiB
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* new_car = (struct car*)calloc(1, sizeof(struct car));
if (new_car == NULL) {
return first;
}
strcpy(new_car->value, target);
new_car->next = NULL;
if (first == NULL) {
return new_car;
} else {
struct car* current = first;
while (current->next != NULL) {
current = current->next;
}
current->next = new_car;
return first;
}
}
void print_train(struct car* first) {
struct car* current = first;
while (current != NULL) {
printf("%s\n", current->value);
current = current->next;
}
}
void cancel_train(struct car* first) {
while (first != NULL) {
struct car* current = first;
first = first->next;
free(current);
}
}
struct car* clear_train(struct car* first, const char* target) {
struct car* new_first = first;
struct car* prev = NULL;
struct car* current = first;
while (current != NULL) {
if (strcmp(current->value, target) == 0) {
if (prev == NULL) {
new_first = current->next;
free(current);
current = new_first;
} else {
prev->next = current->next;
free(current);
current = prev->next;
}
} else {
prev = current;
current = current->next;
}
}
return new_first;
}