Stack, queue and graph data structures implemented in C using linked lists.

1 files changed, 48 insertions, 0 deletions

diff --git a/src/queue.c b/src/queue.c
new file mode 100644
index 0000000..1d7a170
--- /dev/null
+++ b/src/queue.c
@@ -0,0 +1,48 @@
+#include "queue.h"
+#include <stdio.h>
+#include <stdlib.h>
+
+Queue *queueAlloc() {
+  Queue *new = malloc(sizeof(Queue));
+  new->first = NULL;
+  new->last = NULL;
+  return new;
+}
+
+void queueAdd(Queue *queue, int item) {
+  struct queueItem *new = malloc(sizeof(struct queueItem));
+  new->item = item;
+  if (queue->first) {
+    new->next = queue->last;
+    new->previous = NULL;
+    queue->last->previous = new;
+    queue->last = new;
+  } else {
+    new->next = NULL;
+    new->previous = NULL;
+    queue->first = new;
+    queue->last = new;
+  }
+}
+
+int queuePop(Queue *queue) {
+  if (!queue->first) {
+    return -1;
+  }
+  int out = queue->first->item;
+  queue->first = queue->first->previous;
+  return out;
+}
+
+void queueFree(Queue *queue) {
+  struct queueItem *qi = queue->last;
+  struct queueItem *t = NULL;
+  while (qi) {
+    // printf("Address:");
+    // printf("%p\n", (void *)qi);
+    t = qi->next;
+    free(qi);
+    qi = t;
+  }
+  free(queue);
+}