Linked List Problems

Problem: Reverses a singly linked list.
Solution:read

#include <iostream>
using namespace std;

struct node
{
    char c;
    node *next;
};

node *buildlist(char *);
node *revlist(node *);
void freelist(node *);

/**
 ******************************************************************************
 *
 * Reverses a singly linked list
 * 
 * @param argc 
 * @param argv 
 * 
 * @return int 
 *
 ******************************************************************************
 */
int main (int argc, char *argv[])
{
    char buf[128];
    char *str = buf;
    
    cout << "Enter string:";
    str = fgets(buf, 127, stdin);

    if (str)
    {
        size_t len = strlen(str) -1;    // subtract line feed
        str[len] = '\0';                // strip line feed
        printf("in (%03d): %s\n", len, str);

        node *p = buildlist(str);
        node *phead = revlist(p);

        printf("out(%03d): ", len);
        p = phead;
        while (p != NULL)
        {
            printf("%c", p->c);
            p = p->next;
        }
        printf("\n");

        freelist(phead);
    }
    return(0);
}

/**
 ******************************************************************************
 *
 * Builds a singly linked list from the string
 * 
 * @param str 
 * 
 * @return node* pointing to the head of list
 *
 ******************************************************************************
 */
node *buildlist(char *str)
{
    node *head = NULL;
    if (str)
    {
        node *p = new node;
        if (p != NULL)
        {
            head = p;
            p->c = *str++;
            p->next = NULL;

            node *q;
            while (*str != '\0')
            {
                q = new node;
                if (q != NULL)
                {
                    q->c = *str++;
                    q->next = NULL;
                    p->next = q;
                    p = q;
                }
                else {
                    printf("Cannot allocate node\n");
                    break;
                }
            }
        }
        else {
           printf("Cannot allocate head node\n");
        }
    }
    return head;
}

/**
 ******************************************************************************
 *
 * Frees all the nodes in the list
 * 
 * @param p - pointer to head of list
 *
 ******************************************************************************
 */
void freelist(node *p)
{
    node *q;
    while (p != NULL)
    {   
        q = p->next;
        delete p;
        p = q;
    }
}

/**
 ******************************************************************************
 *
 * Reverse the list
 * 
 * @param p - pointer to head of list
 *
 * @return node* pointing to the head of reversed list
 *
 ******************************************************************************
 */
node *revlist(node *p)
{
    node *cur = NULL;

    if (p != NULL)
    {
        node *nxt;
        node *old;

        // initializes local pointers
        cur = old = p;
        nxt = p->next;

        p->next = NULL;         // root becomes tail, sets root->next to null

        while (nxt != NULL)
        {
            cur = nxt;          // operates on this node
            nxt = cur->next;    // advances nxt pointer
            cur->next = old;    // reverses link - points to previous node
            old = cur;          // old points to head node of reversed list
        }
    }
    return cur;                 // points to head of reversed list
}
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