EPA: Linked Queue

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;
+}