#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <string.h>
/*-------------------------*/
struct node
{
    int val;
    struct node* next;
};
typedef struct node NODE;
/*-------------------------*/
NODE* newnode(void)
{
    NODE* pnode;
    pnode = (NODE*)malloc(sizeof(NODE));
    pnode->next = NULL; //(*pnode).next=NULL;
    return pnode;
}
/*-------------------------*/
NODE* push(NODE* root, int val)
{
    NODE* nnode = newnode();
    nnode->val = val;//(*nnode).val;

    if (root== NULL)
        root = nnode;
    else
    {
        nnode->next = root;
        root = nnode;
    }
    return root;
}
/*-------------------------*/
NODE* pop(NODE* root)
{
    NODE* t = root;
    if (root != NULL)
    {
        root = root->next;  free(t);
    }
    return root;
}
/*-------------------------*/
int peek(NODE* root)
{
   return root->val;
}
/*-------------------------*/
void displaystack(NODE* root)
{
    NODE* p = root;
    if (p == NULL)printf("The the stack is empty\n");
    while (p)
    {
        printf("addr:%d(%d)->%i\n", (int)p, p->val, (int)p->next);
        p = p->next;
    }
}
/*-------------------------*/
NODE* findnode(NODE* root, int val)
{
    NODE* p = root;
    while (p)
    {
        if (val == p->val) break;
        p = p->next;
    }
    return p;
}
/*--------PRESS ENTER-------*/
void  press_enter()
{
    printf("Press ENTER to continue");
    getchar();
    while (getchar() != '\n');
}
/*-------------------------*/
int main(int argc, char* argv[])
{
    int key, val;
    NODE* root = NULL, * pnode;
    
    
    do
    {
        system("cls");
        printf("1.Push\n");
        printf("2.Pop\n");
        printf("3.Search node\n");
        printf("4.Print Stack\n");
        printf("5.Peek\n");
        printf("0.Exit\n");
        key = getchar();
        switch (key)
        {
        case '1':printf("val:"); scanf("%i", &val);
            root = push(root, val);
            break;
        case '2':root = pop(root);
            break;
        case '3':printf("val:"); scanf("%i", &val);
            pnode = findnode(root, val);
            if (pnode)printf("%i found in address %u\n", val, (int)pnode);
            else printf("Value not found\n");
            break;
        case '4':displaystack(root);
            break;
        case '5':printf("Val %i on the top of stack\n",peek(root));
            break;
        case '0':break;
        };
        press_enter();
    } while (key != '0');
    
    return 0;
}