算法（23）-单链表-在指定位置增加节点-C++

思路：在K位置增加节点，你要找的是k-1这个点。上代码。
 

Node* addNode(Node* head, int Kth, int m_val)
{
	Node* pre = head;
	Node* cur = head->next;
	Node* newnode = new Node(m_val);
	
	if(pre ==NULL)
	{
		pre = newnode;
		pre->next = pre;
		return pre;
	}	
	int m_index = 0;
	while (cur != NULL)                   //遍历
	{
		if (m_index == (Kth - 1)){	break;}//k-1这个点
		m_index++;//索引增加
		pre = cur;//指针下移
		cur = cur->next;//指针下移
	}		
	pre->next = newnode;
	newnode->next = cur;
	return head;
}