From 754414b451c4ca93d139f61b82bacfa81d236a04 Mon Sep 17 00:00:00 2001
From: Tucker Evans <tuckerevans24@gmail.com>
Date: Sun, 21 Jun 2020 16:26:28 -0400
Subject: Move double ended queue files to own directory

---
 .../double_ended_queue/double_ended_queue.c        | 441 +++++++++++++++++++++
 1 file changed, 441 insertions(+)
 create mode 100644 collections/double_ended_queue/double_ended_queue.c

(limited to 'collections/double_ended_queue/double_ended_queue.c')

diff --git a/collections/double_ended_queue/double_ended_queue.c b/collections/double_ended_queue/double_ended_queue.c
new file mode 100644
index 0000000..015b90b
--- /dev/null
+++ b/collections/double_ended_queue/double_ended_queue.c
@@ -0,0 +1,441 @@
+#include "double_ended_queue.h"
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include <stdio.h>
+
+/*Checks bounds for index (y) in queue*/
+#define DEQ_IN_BOUNDS(x, y) (y < deq_size(x)) \
+
+#define START_SIZE 64;
+
+/*TODO add returned error codes for current void functions
+ * (resize, push, etc.)
+ *
+ * Should all functions return a status code and take in a dest argument?
+ */
+
+/* Double ended queue as a circular buffer
+ * base is pointer to buffer.
+ * beg: postiton of the first element is stored.
+ * end: position for the next element to be stored.
+ * limit: the maximum number of elements.
+ */
+
+struct double_ended_queue {
+	void **base;
+	int beg, end, limit;
+};
+
+deq* deq_new()
+{
+	deq *root;
+
+	root = malloc(sizeof(deq));
+	assert(root);
+
+	root->limit = START_SIZE;
+	root->beg = root->end = 0;
+	root->base = malloc(root->limit * sizeof(void*));
+	assert(root->base);
+
+	return root;
+}
+
+deq* deq_with_capacity(n)
+int n;
+{
+	deq *root;
+
+	root = malloc(sizeof(deq));
+	assert(root);
+
+	root->limit = n;
+	root->beg = root->end = 0;
+	root->base = malloc(root->limit * sizeof(void*));
+	assert(root->base);
+
+	return root;
+}
+
+int deq_size(root)
+deq *root;
+{
+	if (!root)
+		return -1;
+
+	if (root->beg <= root->end)
+		return (root->end - root->beg);
+
+	return (root->limit - root->beg) + (root->end);
+}
+
+int deq_capacity(root)
+deq *root;
+{
+	if (!root) {
+		return -1;
+	} else {
+		return root->limit;
+	}
+}
+
+void deq_resize(root)
+deq *root;
+{
+	void **tmp;
+	int size;
+
+	tmp = malloc(root->limit * 2 * sizeof(void*));
+	assert(tmp);
+
+	if (root->beg <= root->end) {
+		tmp = memcpy(tmp, root->base + root->beg,
+				deq_size(root) * sizeof(void*));
+	} else {
+		/*copy beg<->limit*/
+		size = root->limit - root->beg;
+		tmp = memcpy(tmp, root->base + root->beg, size * sizeof(void*));
+		assert(tmp);
+
+		/*copy base<->end*/
+		tmp = memcpy(tmp + size, root->base,
+				root->end * sizeof(void*));
+		assert(tmp);
+	}
+
+	root->limit *= 2;
+
+	free(root->base);
+	root->base = tmp;
+}
+
+void* deq_index(root, index)
+deq *root;
+int index;
+{
+	void **tmp;
+
+	if (!root || !DEQ_IN_BOUNDS(root,index))
+		return NULL;
+
+	return root->base[(root->beg + index) % root->limit];
+}
+
+void deq_push_front(root, item)
+deq *root;
+void *item;
+{
+	void **tmp;
+
+	if (!root)
+		return;
+
+	if (root->end >= root->limit)
+		deq_resize(root);
+
+	--root->beg;
+	root->beg %= root->limit;
+
+	root->base[root->beg] = item;
+
+	if (root->end == root->beg)
+		root->end = root->limit;
+}
+
+void deq_push_back(root, item)
+deq *root;
+void *item;
+{
+	void **tmp;
+
+	if (!root)
+		return;
+
+	if (root->end >= root->limit)
+		deq_resize(root);
+
+	root->base[root->end++] = item;
+	root->end %= root->limit;
+
+	if (root->end == root->beg)
+		root->end = root->limit;
+}
+
+void deq_set(root, index, item)
+deq *root;
+int index;
+void *item;
+{
+	if (!root || !DEQ_IN_BOUNDS(root, index))
+		return;
+	root->base[(root->beg + index) % root->limit] = item;
+}
+
+void deq_insert(root, index, item)
+deq *root;
+int index;
+void *item;
+{
+	if (!root)
+		return;
+
+	if (index > deq_size(root))
+		return;
+
+	if (root->end >= root->limit)
+		deq_resize(root);
+
+	index = (root->beg + index) % root->limit;
+
+	if (root->beg < root->end) {
+		memmove(root->base + index + 1, root->base + index,
+				(root->end - index) * sizeof(void*));
+		++root->end;
+		root->end = root->end % root->limit;
+	} else if (index < root->end) {
+		memmove(root->base + index + 1,
+				root->base + index,
+				(root->end - index) * sizeof(void*));
+		++root->end;
+	} else {
+		memmove(root->base + root->beg - 1, root->base + root->beg,
+				(index - root->beg) * sizeof(void*));
+		--root->beg;
+	}
+
+	if (root->end == root->beg)
+		root->end = root->limit;
+
+	root->base[index] = item;
+}
+
+void* deq_pop_front(root)
+deq *root;
+{
+	void* tmp;
+	if (!root || root->beg == root->end)
+		return NULL;
+
+	tmp = root->base[root->beg];
+
+	++root->beg;
+	root->beg %= root->limit;
+
+	return tmp;
+}
+
+void* deq_pop_back(root)
+deq *root;
+{
+	if (!root || root->end == root->beg)
+		return NULL;
+
+	--root->end;
+	root->end %= root->limit;
+
+	return root->base[root->end];
+}
+
+void* deq_swap_rm_front(root, index)
+deq *root;
+int index;
+{
+	if (!root || !DEQ_IN_BOUNDS(root,index))
+		return NULL;
+
+	deq_swap(root, 0, index);
+	return deq_pop_front(root);
+}
+
+void* deq_swap_rm_back(root, index)
+deq *root;
+int index;
+{
+	if (!root || !DEQ_IN_BOUNDS(root,index))
+		return NULL;
+
+	deq_swap(root,deq_size(root) - 1,index);
+	return deq_pop_back(root);
+}
+
+void deq_swap(root, i, j)
+deq *root;
+int i, j;
+{
+	int len;
+	void *tmp;
+
+	if (!root)
+		return;
+
+	len = deq_size(root);
+
+	if (i >= len || j >= len)
+		return;
+
+	i += root->beg;
+	i %= root->limit;
+
+	j += root->beg;
+	j %= root->limit;
+
+	tmp = root->base[i];
+	root->base[i] = root->base[j];
+	root->base[j] = tmp;
+}
+
+void deq_remove(root, index)
+deq *root;
+int index;
+{
+	if (!root || !DEQ_IN_BOUNDS(root,index));
+		return;
+
+	index = (root->beg + index) % root->limit;
+
+	root->base[index] = NULL;
+
+	if (root->beg < root->end || index >= root->beg) {
+		memmove(root->base + root->beg + 1,
+				root->base + root->beg,
+				(index - root->beg) * sizeof(void*));
+		++root->beg;
+	} else {
+		memmove(root->base + index, root->base + index + 1,
+				(--root->end - index) * sizeof(void*));
+	}
+}
+
+/* Note: Elements are not freed
+ * deq_clear should be called before if they are no longer needed.
+ */
+void deq_free(root)
+deq *root;
+{
+	free(root->base);
+	root->base = NULL;
+
+	free(root);
+}
+
+void deq_clear(root)
+deq *root;
+{
+	int i, size;
+
+	size = deq_size(root);
+	for (i = 0; i < size; i++) {
+		free(deq_index(root, i));
+	}
+}
+
+void deq_print(root, to_string)
+deq *root;
+char* to_string(void*);
+{
+	int i, size;;
+
+	size = deq_size(root);
+
+	printf("[");
+	for (i = 0; i < size; i++) {
+		printf("%s,", to_string(deq_index(root, i)));
+	}
+	printf("\b]\n");
+}
+
+void deq_debug_print(root)
+deq *root;
+{
+	void **tmp;
+
+	fprintf(stderr, "VEC[b: %p, beg: %d, end:%d]:\n\t ",
+			root->base, root->beg, root->end);
+	for (tmp = root->base; tmp < root->base + root->limit; tmp++){
+		fprintf(stderr, "[%p]", *tmp);
+	}
+	fprintf(stderr, "\n");
+}
+
+deq* deq_cp(root)
+deq *root;
+{
+	deq *copy;
+
+	copy = deq_with_capacity(root->limit);
+	assert(copy->base);
+
+	copy->base = memcpy(copy->base, root->base,
+			root->limit * sizeof(void*));
+	assert(copy->base);
+
+	copy->beg = root->beg;
+	copy->end = root->end;
+
+	return copy;
+}
+
+/*Note: Does not currently reduce memory footprint*/
+void deq_truncate(root, size)
+deq *root;
+int size;
+{
+	if (!root || size > deq_size(root))
+		return;
+
+	root->end = (root->beg + size) % root->limit;
+}
+
+void* deq_front(root)
+deq *root;
+{
+	if (!root)
+		return NULL;
+
+	return root->base[root->beg];
+}
+
+void* deq_back(root)
+deq *root;
+{
+	if (!root)
+		return NULL;
+
+	return root->base[(root->end - 1) % root->limit];
+}
+
+void deq_reserve(root, size)
+deq *root;
+int size;
+{
+	void **tmp;
+	int i, cur_size;
+
+	cur_size = deq_size(root);
+	for (i = root->limit; i - cur_size < size; i*=2);
+
+	tmp = malloc(i * sizeof(void*));
+	assert(tmp);
+
+	if (root->beg <= root->end) {
+		tmp = memcpy(tmp, root->base + root->beg,
+				deq_size(root) * sizeof(void*));
+	} else {
+		/*copy beg<->limit*/
+		size = root->limit - root->beg;
+		tmp = memcpy(tmp, root->base + root->beg, size * sizeof(void*));
+		assert(tmp);
+
+		/*copy base<->end*/
+		tmp = memcpy(tmp + size, root->base,
+				root->end * sizeof(void*));
+		assert(tmp);
+	}
+
+	root->limit *= 2;
+
+	free(root->base);
+	root->base = tmp;
+}
-- 
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