tasks a-s

Task/Queue-Definition/C/queue-definition-1.c

@@ -0,0 +1,50 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef int DATA; /* type of data to store in queue */
+typedef struct {
+	DATA *buf;
+	size_t head, tail, alloc;
+} queue_t, *queue;
+
+queue q_new()
+{
+	queue q = malloc(sizeof(queue_t));
+	q->buf = malloc(sizeof(DATA) * (q->alloc = 4));
+	q->head = q->tail = 0;
+	return q;
+}
+
+int empty(queue q)
+{
+	return q->tail == q->head;
+}
+
+void enqueue(queue q, DATA n)
+{
+	if (q->tail >= q->alloc) q->tail = 0;
+	q->buf[q->tail++] = n;
+	if (q->tail == q->head) {  /* needs more room */
+		q->buf = realloc(q->buf, sizeof(DATA) * q->alloc * 2);
+		if (q->head) {
+			memcpy(q->buf + q->head + q->alloc, q->buf + q->head,
+				sizeof(DATA) * (q->alloc - q->head));
+			q->head += q->alloc;
+		} else
+			q->tail = q->alloc;
+		q->alloc *= 2;
+	}
+}
+
+int dequeue(queue q, DATA *n)
+{
+	if (q->head == q->tail) return 0;
+	*n = q->buf[q->head++];
+	if (q->head >= q->alloc) { /* reduce allocated storage no longer needed */
+		q->head = 0;
+		if (q->alloc >= 512 && q->tail < q->alloc / 2)
+			q->buf = realloc(q->buf, sizeof(DATA) * (q->alloc/=2));
+	}
+	return 1;
+}

Task/Queue-Definition/C/queue-definition-2.c

@@ -0,0 +1,43 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct node_t node_t, *node, *queue;
+struct node_t { int val; node prev, next; };
+
+#define HEAD(q) q->prev
+#define TAIL(q) q->next
+queue q_new()
+{
+	node q = malloc(sizeof(node_t));
+	q->next = q->prev = 0;
+	return q;
+}
+
+int empty(queue q)
+{
+	return !HEAD(q);
+}
+
+void enqueue(queue q, int n)
+{
+	node nd = malloc(sizeof(node_t));
+	nd->val = n;
+	if (!HEAD(q)) HEAD(q) = nd;
+	nd->prev = TAIL(q);
+	if (nd->prev) nd->prev->next = nd;
+	TAIL(q) = nd;
+	nd->next = 0;
+}
+
+int dequeue(queue q, int *val)
+{
+	node tmp = HEAD(q);
+	if (!tmp) return 0;
+	*val = tmp->val;
+
+	HEAD(q) = tmp->next;
+	if (TAIL(q) == tmp) TAIL(q) = 0;
+	free(tmp);
+
+	return 1;
+}

Task/Queue-Definition/C/queue-definition-3.c

@@ -0,0 +1,22 @@
+int main()
+{
+	int i, n;
+	queue q = q_new();
+
+	for (i = 0; i < 100000000; i++) {
+		n = rand();
+		if (n > RAND_MAX / 2) {
+		//	printf("+ %d\n", n);
+			enqueue(q, n);
+		} else {
+			if (!dequeue(q, &n)) {
+			//	printf("empty\n");
+				continue;
+			}
+		//	printf("- %d\n", n);
+		}
+	}
+	while (dequeue(q, &n));// printf("- %d\n", n);
+
+	return 0;
+}

Task/Queue-Definition/C/queue-definition-4.c

@@ -0,0 +1,47 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include <sys/queue.h>
+
+struct entry {
+  int value;
+  TAILQ_ENTRY(entry) entries;
+};
+
+typedef struct entry entry_t;
+
+TAILQ_HEAD(FIFOList_s, entry);
+
+typedef struct FIFOList_s FIFOList;
+
+
+bool m_enqueue(int v, FIFOList *l)
+{
+  entry_t *val;
+  val = malloc(sizeof(entry_t));
+  if ( val != NULL ) {
+    val->value = v;
+    TAILQ_INSERT_TAIL(l, val, entries);
+    return true;
+  }
+  return false;
+}
+
+bool m_dequeue(int *v, FIFOList *l)
+{
+  entry_t *e = l->tqh_first;
+  if ( e != NULL ) {
+    *v = e->value;
+    TAILQ_REMOVE(l, e, entries);
+    free(e);
+    return true;
+  }
+  return false;
+}
+
+bool isQueueEmpty(FIFOList *l)
+{
+  if ( l->tqh_first == NULL ) return true;
+  return false;
+}