第10章，基本数据结构（栈，队列）

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

typedef struct _stack{
	int* arr;
	int top, size;
}stack;
stack createStack(int size)
{
	stack st;
	st.arr = (int*)malloc(size*sizeof(int));
	st.top = -1;
	st.size = size;
	return st;
}
int isEmptyStack(stack &s)
{
	return s.top == -1;
}
void push(stack &s, int val)
{
	if (s.top == s.size - 1){
		int *tmp = s.arr;
		s.arr = (int*)malloc(2 * s.size*sizeof(int));
		memcpy(s.arr, tmp, s.size*sizeof(int));
		s.size = s.size * 2;
	}
	++s.top;
	s.arr[s.top] = val;
}
int pop(stack &s)
{
	if (isEmptyStack(s)){
		printf("stack is empty\n");
		exit(-1);
	}
	--s.top;
	return s.arr[s.top + 1];
}


typedef struct _queue{
	int *arr;
	int tail, head, size;
}queue;
queue createQueue(int size)
{
	queue q;
	q.tail = q.head = 0;
	q.arr = (int*)malloc(size*sizeof(int));
	q.size = size;
	return q;
}
void enqueue(queue &q, int val)
{
	if (q.head == (q.tail + 1) % q.size){
		int *tmp = q.arr;
		q.arr = (int*)malloc(2 * q.size*sizeof(int));
		memcpy(q.arr, tmp, q.size*sizeof(int));
		q.size = 2 * q.size;
	}
	q.arr[q.tail] = val;
	q.tail = (q.tail + 1) % q.size;
}
int dequeue(queue &q)
{
	if (q.tail == q.head){
		printf("queue is empty\n");
		exit(-1);
	}
	int res = q.arr[q.head];
	q.head = (q.head + 1) % q.size;
	return res;
}

int main()
{
	int a[] = { 1, 2, 3, 4, 5, 6, 7 };
	stack ss = createStack(5);
	for (int i = 0; i < 7; ++i)
		push(ss, a[i]);
	printf("%d\n", ss.size);
	for (int i = 0; i < 7; ++i)
		printf("%d\t", pop(ss));
	printf("\n");

	queue q = createQueue(5);
	for (int i = 0; i < 5; ++i)
		enqueue(q, a[i]);
	dequeue(q); dequeue(q);
	enqueue(q, 100); enqueue(q,200);
	for (int i = 0; i <6; ++i)
		printf("%d\t", dequeue(q));
}