1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 | #include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
// STEP 0: Original syntax
//
// Problem: (*curr).value is ugly.
// Solution: curr -> value
//
// Problem: while loop is more error-prone than a for loop (and violates code quality
// standard for the course).
// Solution: Use a for loop to iterate over a linked list.
//
// Problem: Making the struct objects on the stack (in function with name) is limiting.
// Solution: Use malloc(…)
//
// Problem: Typing `struct Node` is more cumbersome than typing `Node`.
// Solution: Don't be lazy.
//
// Problem²: I am lazy.
// Solution: Use typedef.
typedef struct _Node {
int value;
struct _Node* next;
} Node;
void print_list(Node* head) { // print_list(…) now takes address of the head node
for(Node* curr = head; curr != NULL; curr = curr -> next) {
printf("[%d]", curr -> value);
// If this is not the tail, then print a '─' to connect to the next node.
if(curr -> next != NULL) {
printf("─");
}
}
printf("\n");
}
void _append(int value, Node** a_head, Node** a_tail) {
Node* new_node = malloc(sizeof(*new_node)); // allocate space for one new node
new_node -> value = value; // set its .value field
if(*a_head == NULL) { // list was empty
*a_head = new_node;
*a_tail = new_node;
// We now have a list of size 1.
}
else {
(*a_tail) -> next = new_node;
new_node -> next = NULL;
*a_tail = new_node; // Don't forget!!! Every time we add a node to the end,
// the tail changes.
// We now have a list of size ≥2
}
}
int main(int argc, char* argv[]) {
Node* head = NULL; // linked list of size 0.
Node* tail = head;
_append(5, &head, &tail);
print_list(head);
_append(6, &head, &tail);
print_list(head);
_append(7, &head, &tail);
print_list(head);
print_list(head);
return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */
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