recursion_sample2.cpp

#include <iostream>
#include <algorithm>

using namespace std;

struct ListNode {
	int data;
	ListNode * next;
}; typedef ListNode * ListPtr;

/**
 * countNodeFromList
 * count node from list by recursion
 * @param ListNode * ptr : node root
 */
int CountNodeFromList(ListNode * ptr){
	if(ptr == NULL) return 0;
	int behind_count = CountNodeFromList(ptr->next);
	return behind_count + 1;
}

/**
 * OutputListFromFront
 * ListNode->data to standard output by front
 * @param ListNode * ptr : node root
 */
void OutputListFromFront(ListNode * ptr){
	if(ptr != NULL){
		cout<< ptr->data <<endl;
		OutputListFromFront(ptr->next);
	}
}

/**
 * OutputListFromRear
 * ListNode->data to standard output by read
 * @param ListNode * ptr : node root
 */
void OutputListFromRear(ListNode * ptr){
	if(ptr != NULL){
		OutputListFromRear(ptr->next);
		cout<< ptr->data <<endl;
	}
}

int main(){
	cout<<"start main!"<<endl;

	ListPtr list_root;
	ListNode * l1 = new ListNode; l1->data =9;
	ListNode * l2 = new ListNode; l2->data =4;
	ListNode * l3 = new ListNode; l3->data =10;
	ListNode * l4 = new ListNode; l4->data =18;
	ListNode * l5 = new ListNode; l5->data =3;
	ListNode * l6 = new ListNode; l6->data =43;
	ListNode * l7 = new ListNode; l7->data =76;
	ListNode * l8 = new ListNode; l8->data =22;

	list_root = l1; l1->next = l2; l2->next = l3; l3->next = l4;
	l4->next = l5; l5->next = l6; l6->next = l7; l7->next = l8;

	int count = CountNodeFromList(list_root);
	cout<<"Node Count : "<<count<<endl;
	cout<<"------------------------------"<<endl;
	OutputListFromFront(list_root);
	cout<<"------------------------------"<<endl;
	OutputListFromRear(list_root);

	return 0;
}