《C算法》读书笔记（5）：单向链表逆序

P71,3-10

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;

typedef struct node *link;
struct node
{
int item;
link next;
};
int n;

void visit(link p)
{
printf("%d ", p->item);
}

void traverse(link head)
{
link p = head;
while(p != NULL)
{
printf("%d ", p->item);
p = p->next;
}
printf("\n");
}

link reverse(link head)
{
link p = head, next, prev = NULL;
while(p != NULL)
{
next = p->next;
p->next = prev;
prev = p;
p = next;
}
return prev;
}

int main()
{
freopen("in.txt", "r", stdin);
freopen("out.txt", "w", stdout);
scanf("%d", &n);
link p, head;
head = p = (link)malloc(sizeof(node)); p->item = 1, p->next = p;
for(int i = 2; i <= n; ++ i)
{
p = (p->next = (link)malloc(sizeof(node)));
p->item = i, p->next = NULL;
}
traverse(head);
link tail = reverse(head);
traverse(tail);

return 0;
}