Linked List

main.cpp

#include <iostream>
using namespace std;

struct nodeType
{
	int info;
	nodeType *link;
};

nodeType* buildListForward();
nodeType* buildListBackward();

int main() {
	nodeType *first;

	first = buildListForward();

	while (first != nullptr) {
		cout << first->info << " ";
		first = first->link;
	}

	return 0;
}

// build a linked list forwards
nodeType* buildListForward() {
	nodeType *first, *last, *newNode;
	int num;
	cout << "Enter a list of integers ending with -999" << endl;
	cin >> num;

	first = nullptr;

	while (num != -999) {
		newNode = new nodeType;
		newNode->info = num;
		newNode->link = nullptr;

		if (first == nullptr) {
			first = newNode;
			last = newNode;
		}
		else {
			last->link = newNode;
			last = newNode;
		}
		cin >> num;
	}

	return first;
}

// build a linked list backwards
nodeType* buildListBackward() {
	nodeType *first, *newNode;
	int num;

	cout << "Enter a list of integers ending with -999" << endl;
	cin >> num;

	first = nullptr;

	while (num != -999) {
		newNode = new nodeType;
		newNode->info;
		newNode->link = first;
		first = newNode;
		
		cin >> num;
	}

	return first;
}