简直offer之链表的插入和删除

public static ListNode deleteNode(ListNode head,int value){
        if(head==null){
            return null;
        }
        ListNode toBeDelete = null;
        if(head.val==value){
            toBeDelete = head;
        }
        else{
            ListNode pHead = head;
            while(pHead.next!=null&&pHead.next.val!=value){
                pHead = pHead.next;
            }
            if(pHead.next!=null&&pHead.next.val==value){
                toBeDelete = pHead.next;
                pHead.next = pHead.next.next;
            }
        }
        if(toBeDelete!=null){
            toBeDelete = null;
        }
        return head;
    }