init

The-Nook-GamesTM/Proficiencies/evaluate_rpn.c

@@ -0,0 +1,3 @@
+#include "evaluate_rpn.h"
+
+int evaluate_rpn(struct queue *queue);

The-Nook-GamesTM/Proficiencies/evaluate_rpn.h

@@ -0,0 +1,8 @@
+#ifndef EVALUATE_RPN_H
+#define EVALUATE_RPN_H
+
+#include "queue.h"
+
+int evaluate_rpn(struct queue *queue);
+
+#endif /* ! EVALUATE_RPN_H*/

The-Nook-GamesTM/Proficiencies/main.c

@@ -0,0 +1 @@
+int main(int argc, char** argv);

The-Nook-GamesTM/Proficiencies/parse_exp.c

@@ -0,0 +1,3 @@
+#include "parse_exp.h"
+
+struct queue *parse_expression(const char *str);

The-Nook-GamesTM/Proficiencies/parse_exp.h

@@ -0,0 +1,8 @@
+#ifndef PARSE_EXP_H
+#define PARSE_EXP_H
+
+#include "queue.h"
+
+struct queue *parse_expression(const char *str);
+
+#endif /* ! PARSE_EXP_H */

The-Nook-GamesTM/Proficiencies/queue.c

@@ -0,0 +1,41 @@
+#include "queue.h"
+
+struct queue *enqueue(struct queue *queue, struct expression_element* element) {
+    struct queue *new_elt = calloc(1,sizeof(struct queue));
+
+    new_elt->data = element;
+
+    if(!queue)
+        return new_elt;
+
+    struct queue* current = queue;
+
+    while(current->next)
+        current = current->next;
+
+    current->next = new_elt;
+
+    return queue;
+}
+
+struct expression_element* dequeue(struct queue **queue) {
+    if (!queue || !*queue)
+        return NULL;
+    
+    struct queue* removed = *queue;
+    struct expression_element* res = removed->data;
+
+    *queue = removed->next;
+    free(removed);
+
+    return res;
+}
+
+void queue_destroy(struct queue **queue) {
+    if(!queue)
+        return;
+    while (*queue) {
+        struct expression_element* dequeued = dequeue(queue);
+        free(dequeued);
+    }
+}

The-Nook-GamesTM/Proficiencies/queue.h

@@ -0,0 +1,31 @@
+#ifndef QUEUE_H
+#define QUEUE_H
+
+#include <stdlib.h>
+
+union element_type
+{
+    int operand;
+    char operator;
+};
+
+enum element_tag {
+    TOKEN_OPERAND,
+    TOKEN_OPERATOR
+};
+
+struct expression_element {
+    enum element_tag tag;
+    union element_type data;
+};
+
+struct queue {
+    struct expression_element* data;
+    struct queue *next;
+};
+
+struct queue *enqueue(struct queue *queue, struct expression_element* element);
+struct expression_element* dequeue(struct queue **queue);
+void queue_destroy(struct queue **queue);
+
+#endif /* ! QUEUE_H */

The-Nook-GamesTM/Proficiencies/stack.c

@@ -0,0 +1,36 @@
+#include "stack.h"
+
+struct stack *stack_push(struct stack *s, struct expression_element e)
+{
+    struct stack *new = malloc(sizeof(struct stack));
+    new->next = NULL;
+    new->data = e;
+    if (s == NULL)
+        return new;
+    new->next = s;
+    return new;
+}
+
+struct stack *stack_pop(struct stack *s)
+{
+    if (!s)
+        return NULL;
+    struct stack *next = s->next;
+    free(s);
+    return next;
+}
+
+void stack_destroy(struct stack **s)
+{
+    if(!s)
+        return;
+    while (*s)
+    {
+        *s = stack_pop(*s);
+    }
+}
+
+struct expression_element stack_peek(struct stack *s)
+{
+    return s->data;
+}

The-Nook-GamesTM/Proficiencies/stack.h

@@ -0,0 +1,40 @@
+#ifndef STACK_H
+#define STACK_H
+
+#include <stdlib.h>
+
+union element_type
+{
+    int operand;
+    char operator;
+};
+
+enum element_tag {
+    TOKEN_OPERAND,
+    TOKEN_OPERATOR
+};
+
+struct expression_element {
+    enum element_tag tag;
+    union element_type data;
+};
+
+struct stack {
+    struct expression_element data;
+    struct stack *next;
+};
+
+/* Push a new element to the stack and returns the new top */
+struct stack *stack_push(struct stack *s, struct expression_element element);
+
+/* Pop from the stack and returns its new top */
+struct stack *stack_pop(struct stack *s);
+
+/* Empty and frees the whole stack */
+void stack_destroy(struct stack **s);
+
+/* Returns the current top of the stack */
+struct expression_element stack_peek(struct stack *s);
+
+
+#endif /* ! STACK_H */