/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可
 *
 * 
 * @param head ListNode类 
 * @return ListNode类
 */
struct ListNode* ReverseList(struct ListNode* head ) {
    // write code here
    struct ListNode* phead = (struct ListNode*)malloc(sizeof(struct ListNode));
    phead->next = NULL;
    while(head)
    {
        struct ListNode* next = head->next;
        head->next = phead->next;
        phead->next = head;
        head = next;
    }
    return phead->next;
}