【每日一题-16】重建二叉树&C模拟实现C++继承多态

由前序遍历和中序遍历重建二叉树

void reBuildTree(vector<int> pre, int begin1, int end1, \
				 vector<int> in, int begin2, int end2)
{
	if (pre.size() != in.size())
		return ;
	int mid = begin2;
	while (begin1 < end1)
	{
		mid++;
		if (pre[begin1] == in[mid])
			break;
	}
	reBuildTree(pre, begin1++, end1, in, begin2, mid - 1);
	reBuildTree(pre, begin1++, end1, in, mid + 1, end2);
}

typedef void(*FUNC);

struct A
{
	FUNC f;		//通过结构体的嵌套实现类之间的继承
	int a;
};
struct B
{
	A _a;
	int b;
};
void funA()
{
	printf("funA\n");
}
void funB()
{
	printf("funB\n");
}

void fun(A* ptr)
{
	ptr->f();
}

int main()
{
	A a;
	B b;
	a.f = funA;
	b._a.f = funB;
	fun(&a);
	fun((A*)&b);
	system("pause");
	return 0;
}