203. Remove Linked List Elements
Easy
Remove 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
package leetcode.easy;
/**
* Definition for singly-linked list. public class ListNode { int val; ListNode
* next; ListNode(int x) { val = x; } }
*/
public class RemoveLinkedListElements {
private static void print(ListNode l) {
if (l == null) {
return;
}
while (l != null) {
System.out.print(l.val);
if (l.next != null) {
System.out.print("->");
}
l = l.next;
}
System.out.println();
}
public ListNode removeElements(ListNode head, int val) {
if (head == null) {
return head;
}
if (head.val == val) {
return removeElements(head.next, val);
} else {
ListNode p = head;
while (p.next != null) {
if (p.next.val == val) {
p.next = p.next.next;
} else {
p = p.next;
}
}
return head;
}
}
@org.junit.Test
public void test() {
ListNode ln1 = new ListNode(1);
ListNode ln2 = new ListNode(2);
ListNode ln3 = new ListNode(6);
ListNode ln4 = new ListNode(3);
ListNode ln5 = new ListNode(4);
ListNode ln6 = new ListNode(5);
ListNode ln7 = new ListNode(6);
ln1.next = ln2;
ln2.next = ln3;
ln3.next = ln4;
ln4.next = ln5;
ln5.next = ln6;
ln6.next = ln7;
ln7.next = null;
print(ln1);
print(removeElements(ln1, 6));
}
}