16_II / произвед всех отриц элементов

#include <iostream.h>

struct sp {int data; sp * next;};

void create_sp ( sp * &nach, int n){
	sp *p;
	nach=NULL;
	cout<<"soisok=";
	for (int i=1; i<=n; i++){
		p = new sp; 
		cin>> p->data; 
		p->next = nach;
		nach = p;}}

void pokaz_sp (sp * nach){
	sp * p; 
	p = nach;
	while (p != NULL){
		cout<<p->data<<' ';	
		p = p->next;}}

int proiz_otr (sp * nach){
	sp * p; 
	int  s; 
	p = nach; 
	s = 1;
	while (p != NULL){
		if (p->data < 0)
			s=s*p->data;
		p = p->next;}
	return s;
}

void main(int argc, char* argv[]){
	int n;
	sp * nach1;	
	cout << "n=";
	cin >> n;
	create_sp (nach1, n);
	pokaz_sp (nach1);
	cout<<endl;
	cout<<"proiz.otricat.chisel = "<<proiz_otr (nach1)<<endl;
	}