From 0e153f547a5251b7b9571ab1a932b1cb2ec1e8c1 Mon Sep 17 00:00:00 2001
From: Valentin Gehrke <madmaurice@zom.bi>
Date: Sun, 21 Feb 2016 16:15:08 +0100
Subject: [PATCH] EPA: Linked Queue
---
linkedqueue.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 84 insertions(+)
create mode 100644 linkedqueue.c
diff --git a/linkedqueue.c b/linkedqueue.c
new file mode 100644
index 0000000..80518e7
--- /dev/null
+++ b/linkedqueue.c
@@ -0,0 +1,84 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+typedef struct node {
+ int element;
+ struct node* next;
+} Node;
+
+typedef struct queue {
+ Node* head;
+ Node* tail;
+} *Queue;
+
+Queue qCreate() {
+ Queue q = malloc(sizeof(struct queue));
+ q->head = NULL;
+ q->tail = NULL;
+ return q;
+}
+
+int qEmpty(Queue q) {
+ return q->head == NULL;
+}
+
+void qPush(Queue q, int element) {
+ Node * n = malloc(sizeof(Node));
+ n->element = element;
+ n->next = NULL;
+ if(qEmpty(q)) {
+ q->head = q->tail = n;
+ } else {
+ q->tail->next = n;
+ q->tail = n;
+ }
+}
+
+int qPop(Queue q) {
+ assert(!qEmpty(q));
+ Node* n = q->head;
+ q->head = n->next;
+ if(q->head == NULL) {
+ q->tail == NULL;
+ }
+ int element = n->element;
+ free(n);
+ return element;
+}
+
+void qClear(Queue q) {
+ Node* iter = q->head;
+ Node* tmp;
+ while(iter != NULL) {
+ tmp = iter;
+ iter = iter->next;
+ free(tmp);
+ }
+ q->head = NULL;
+ q->tail = NULL;
+}
+
+void qFree(Queue q) {
+ qClear(q);
+ free(q);
+}
+
+int main( int argc, char *argv[] ) {
+ Queue q = qCreate();
+ for(int i = 0; i < 10; i++) {
+ qPush(q,i*i);
+ }
+
+ while(!qEmpty(q)) printf("%d ", qPop(q));
+ printf("\n");
+
+ for(int i = 0; i < 10; i++) qPush(q,i);
+ for(int i = 0; i < 5; i++) qPop(q);
+ printf("%d\n", qPop(q));
+ qClear(q);
+ assert(qEmpty(q));
+ qFree(q);
+
+ return 0;
+}