From 4e36efdf20ed9f7be0c98743b6ddfa54f472c849 Mon Sep 17 00:00:00 2001
From: Blake Romero <blake@blkrom.com>
Date: Fri, 10 Oct 2025 17:43:54 +0100
Subject: Rename & refactor list data structure

---
 src/lib/list.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib/list.h |  52 +++++++++++++++++++++++++
 2 files changed, 171 insertions(+)
 create mode 100644 src/lib/list.c
 create mode 100644 src/lib/list.h

(limited to 'src/lib')

diff --git a/src/lib/list.c b/src/lib/list.c
new file mode 100644
index 0000000..26c8cc1
--- /dev/null
+++ b/src/lib/list.c
@@ -0,0 +1,119 @@
+// Implementation of a Linked List
+//
+// TODO: recursive implementation for list_free()
+//
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "list.h"
+
+Node* node_init(int value) {
+  Node* n = (Node*) malloc(sizeof(Node));
+  n->value = value;
+  n->next = NULL;
+  return n;
+}
+
+void list_print(Node* head) {
+  Node* node = head;
+  printf("[ ");
+  while (node != NULL) {
+    printf("%i ", node->value);
+    node = node->next;
+  }
+  printf("]\n");
+  free(node);
+}
+
+void list_vprint(Node* head) {
+  Node* node = head;
+  while (node != NULL) {
+    printf("[*] %i\n", node->value);
+    node = node->next;
+    printf(" |\n");
+  }
+  printf("[/] %s\n", (char*) node);
+}
+
+int list_length(Node* head) {
+  Node* n = head;
+  int i = 0;
+  for (; n != NULL; ++i) n = n->next;
+  return i;
+}
+
+void list_push(Node** head, int value) {
+  Node* n = node_init(value);
+  n->next = *head;
+  *head = n;
+}
+
+int list_pop(Node** head) {
+  int val = (*head)->value;
+  *head = (*head)->next;
+  return val;
+}
+
+void list_append(Node* head, int value) {
+  Node* n = head;
+  while (n->next != NULL) n = n->next;
+  n->next = node_init(value);
+}
+
+void list_insert(Node** head, int value, int index) {
+  Node* n = *head;
+  Node* cur = NULL;
+  Node* node = node_init(value);
+  int i = 0;
+  while (n->next != NULL && i < index) {
+    cur = n;
+    n = n->next;
+    ++i;
+  }
+  cur->next = node;
+  node->next = n;
+}
+
+void list_free(Node** head) {
+  while (*head != NULL) {
+    Node* n = *head;
+    *head = (*head)->next;
+    free(n);
+  }
+  *head = NULL;
+}
+
+int list_rmlast(Node** head) {
+  Node* n = *head;
+  Node* cur = NULL;
+  while (n->next != NULL) {
+    cur = n;
+    n = n->next;
+  }
+  int val = n->value;
+  cur->next = NULL;
+  free(n);
+  return val;
+}
+
+int list_rm(Node** head, int index) {
+  Node* n = *head;
+  Node* cur = NULL;
+  if (index == -1) {
+    while (n->next != NULL) {
+      cur = n;
+      n = n->next;
+    }
+  } else {
+    int i = 0;
+    while (n->next != NULL && i < index) {
+      cur = n;
+      n = n->next;
+      ++i;
+    }
+  }
+  cur->next = n->next;
+  int val = n->value;
+  free(n);
+  return val;
+}
diff --git a/src/lib/list.h b/src/lib/list.h
new file mode 100644
index 0000000..58a7751
--- /dev/null
+++ b/src/lib/list.h
@@ -0,0 +1,52 @@
+#ifndef LIST_H
+#define LIST_H
+
+#include <stdio.h>
+#include <stdlib.h>
+
+// Node
+typedef struct Node {
+  int value;
+  struct Node* next;
+} Node;
+
+// Create & initialise a new node
+Node* node_init(int value);
+
+// Print linked list values
+void list_print(Node* head);
+void list_vprint(Node* head);
+
+// Return number of nodes in list
+// O(n)
+int list_length(Node* head);
+
+// Prepend a value to the list
+// O(1)
+void list_push(Node** head, int value);
+
+// Pop (remove) first node
+// O(1)
+int list_pop(Node** head);
+
+// Append value to the end of the list
+// O(n)
+void list_append(Node* head, int value);
+
+// Insert a value to the list at index
+// O(n)
+void list_insert(Node** head, int value, int index);
+
+// Free nodes from memory
+// O(n)
+void list_free(Node** head);
+
+// Remove last node
+// O(n)
+int list_rmlast(Node** head);
+
+// Remove node at index
+// O(n)
+int list_rm(Node** head, int index);
+
+#endif //LIST_H
-- 
cgit