Add initial stack implementation

source/data_structures/stack.c

@@ -0,0 +1,29 @@
+#include "stack.h"
+
+#include "stddef.h"
+
+void stack_reset(Stack* stack)
+{
+    stack->top = -1;
+}
+
+bool stack_empty(Stack* stack)
+{
+    return stack->top < 0;
+}
+
+int stack_len(Stack* stack)
+{
+
+}
+
+void stack_push(Stack* stack, void* data)
+{
+    if (stack->top < stack->max)
+        stack->data_array[++stack->top] = data;
+}
+
+void* stack_pop(Stack* stack)
+{
+    return (stack->top < 0) ? NULL : stack->data_array[stack->top--];
+}