LeecCode Reverse Linked List; Reverse a singly linked list.

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
struct ListNode* reverseList(struct ListNode* head) {
    struct ListNode *back;
    struct ListNode *fore;
    if(head==NULL || head->next==NULL)
    {
        ;  //如果鏈表只有一個節點或者爲空鏈，不進行任何操作
    }
    else
    {
        back = head;
        fore = back->next;
        while(back->next != NULL)
        {
            back->next = fore->next;
            fore->next = head;
            head = fore;
            fore = back->next;
        }
    }
    return  head;
}