assignment problem 2

assignment1/problem2/stack.c

@@ -0,0 +1,108 @@
+/*
+ * Author: Walter
+ * Student ID: 1930006025
+ * Assignment_1_problem_2
+ * stack lib, allow to create empty stack
+ */
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <assert.h>
+
+#include "stack.h"
+
+bool CreateStack(Stack *stack, int size) {
+	/* check, allow create empty stack */
+	assert(size >= 0);
+
+	/* memory allocate */
+	stack->data = (char *)malloc(sizeof(char) * size);
+	if (stack->data == NULL) {
+		return false;
+	}
+
+	/* init attribute */
+	stack->top = -1;
+	stack->size = size;
+
+	return true;
+}
+
+bool IsEmpty(Stack *stack) {
+	/* if empty, stack->top = -1 */
+	return stack->top < 0;
+}
+
+bool IsFull(Stack *stack) {
+	/* if full, stack->top = stack->size */
+	return stack->top >= stack->size;
+}
+
+bool Top(Stack *stack, char *x) {
+	/* check empty */
+	if (IsEmpty(stack)) {
+		return false;
+	}
+
+	/* get top */
+	*x = stack->data[stack->top];
+
+	return true;
+}
+
+bool Push(Stack *stack, char x) {
+	/* check */
+	if (IsFull(stack)) {
+		return false;
+	}
+
+	/* push */
+	stack->data[++stack->top] = x;
+
+	return true;
+}
+
+bool Pop(Stack *stack, char *x) {
+	/* check */
+	if (IsEmpty(stack)) {
+		return false;
+	}
+
+	/* get x, and top - 1 */
+	*x = stack->data[stack->top--];
+	return true;
+}
+
+void DisplayStack(Stack *stack) {
+	char *top_p = stack->data + stack->top;
+
+	/* print the top pointer hint */
+	printf("top --> ");
+	
+	/* loop for stack data */
+	for (; top_p >= stack->data; top_p--) {
+
+		/* print top --> hint */
+		if (top_p != stack->data + stack->top) {
+			printf("        ");
+		}
+
+		printf("|  %c  |\n", *top_p);
+	}
+
+	/* print top --> hint */
+	if (top_p != stack->data + stack->top) {
+		printf("        ");
+	}
+
+	printf("+--------------+\n");
+}
+
+void DestroyStack(Stack *stack) {
+	free(stack->data);
+	stack->data = NULL;
+	stack->size = 0;
+	stack->top = -1;
+}