Remove Linked List Elements(leetcode203)

emove all elements from a linked list of integers that have value val.

Example:

Input: 1->2->6->3->4->5->6, val = 6 Output: 1->2->3->4->5

实现：

public static ListNode removeElements(ListNode head, int val) {

ListNode temp = head;
ListNode pre = null;
while(null != temp) {
    if (temp.val == val) {

        if (null == pre) {
            head = temp.next;
        }else{
            pre.next = temp.next;
        }

    }else {
        pre = temp;
    }
    temp = temp.next;


}
return head;

}

测试一下：

int array[] = {1,2,6,3,4,5,6}; ListNode head = ListNode.buildeListNode(array); ListNode.printListNode(head); ListNode.printListNode(removeElements(head,6));

这里写点方法构建链表，和输出

public static void printListNode(ListNode head) { List list = new ArrayList(); ListNode temp = head; while(null != temp){ list.add(temp.val); temp = temp.next; } System.out.println(list); }

public static ListNode buildeListNode(int[] array) { ListNode head = null; //当前节点 ListNode temp = null; for (int i = 0;i< array.length;i++){ if(i == 0){ head = new ListNode(array[i]); temp = head; }else{ ListNode newNode = new ListNode(array[i]); temp.next = newNode; temp = newNode; } } return head; }

git：https://github.com/woshiyexinjie/leetcode-xin/tree/master/src/main/java/com/helloxin/leetcode/algorithms