Initial commit

1 files changed, 65 insertions, 0 deletions

diff --git a/stack.c b/stack.c
new file mode 100644
index 0000000..1014785
--- /dev/null
+++ b/stack.c
@@ -0,0 +1,65 @@
+#include "./stack.h"
+#include <stdbool.h>
+#include <stdlib.h>
+
+bool stack_is_empty(stack *s)
+{
+	if (!s || s->top == -1) {
+		return true;
+	}
+
+	return false;
+}
+
+stack *new_stack(size_t size)
+{
+        stack *s = malloc(sizeof(stack));
+	if (!s)
+		return NULL;
+
+	s->data = malloc(size * sizeof(void *));
+	if (!s->data) {
+		free(s);
+		return NULL;
+	}
+
+	s->capacity = size;
+	s->top = -1;
+	return s;
+}
+
+void free_stack(stack *s)
+{
+	if (!s)
+		return;
+
+	free(s->data);
+	free(s);
+}
+
+void *pop(stack *s)
+{
+	if (stack_is_empty(s))
+		return NULL;
+	return s->data[s->top--];
+}
+
+void *peek(stack *s)
+{
+	if (stack_is_empty(s))
+		return NULL;
+	return s->data[s->top];
+}
+
+void *push(stack *s, void *data)
+{
+	if (!s)
+		return NULL;
+
+	if (s->top + 1 >= s->capacity) {
+		s->capacity *= 2;
+		s->data = realloc(s->data, sizeof(void *) * s->capacity);
+	}
+
+	return s->data[++s->top] = data;
+}