public void removeNode(ListNode a, int val) {
if (a.val == val) {
// ListNode b = a.next;
// a.val = b.val;
// a.next = b.next;
a.val = a.next.val;
a.next = a.next.next;
} else {
while (a.next.val != val) {
a = a.next;
}
a.next = a.next.next;
}
}
public void insertNthNode(ListNode a, int n, int val) {
if (n == 1) { // !!!!!!!!!!!!!!!!!!
a = insertFrontNode(a, val);
} else {
ListNode b = new ListNode(val);
int i = 1;
while (a.next != null && i != n - 1) {
i++;
a = a.next;
}
b.next = a.next;
a.next = b;
}
}
public void removeNthNode(ListNode a, int n) {
if (n == 1) {
// ListNode b = a.next;
// a.val = b.val;
// a.next = b.next;
a.val = a.next.val;
a.next = a.next.next;
} else {
int i = 1;
while (a.next != null && i != n - 1) {
i++;
a = a.next;
}
a.next = a.next.next;
}
}
public static void addNode(ListNode a, int val) {
ListNode b = new ListNode(val);
while (a.next != null) {
a = a.next;
}
a.next = b;
}
public static void main(String args[]) {
ListNode a = new ListNode(1);
ListNode b = new ListNode(2);
ListNode c = new ListNode(3);
ListNode d = new ListNode(4);
ListNode e = new ListNode(5);
a.next = b;
b.next = c;
c.next = d;
d.next = e;
TreeNode ans = sortedListToBST(a);
System.out.println("root= " + ans.val);
System.out.println("root.left= " + ans.left.val);
System.out.println("root.right= " + ans.right.val);
TreeNode one = ans.left;
System.out.println(one.right.val);
}
public ListNode mergeKLists(List<ListNode> lists) {
SmallRootHeap<ListNode2> heap = new SmallRootHeap<ListNode2>();
for (ListNode node : lists) {
if (node != null) heap.add(new ListNode2(node));
}
if (heap.empty()) return null;
ListNode head = heap.pop(), ptr = head;
if (ptr.next != null) {
heap.add(new ListNode2(ptr.next));
ptr.next = null;
}
while (!heap.empty()) {
ptr.next = heap.pop();
ptr = ptr.next;
if (ptr.next != null) {
heap.add(new ListNode2(ptr.next));
ptr.next = null;
}
}
return head;
}
public ListNode mergeKLists(ListNode[] lists) {
int len = 0;
for (int i = 0; i < lists.length; i++)
if (lists[i] != null) {
lists[len++] = lists[i];
}
buildHeap(lists, len);
ListNode resHead = new ListNode(0);
ListNode resRear = resHead;
while (len > 1) {
resRear.next = lists[0];
resRear = lists[0];
if (lists[0].next == null) {
lists[0] = lists[len - 1];
len--;
sortHeap(lists, 0, len);
} else {
lists[0] = lists[0].next;
sortHeap(lists, 0, len);
}
}
resRear.next = lists[0];
return resHead.next;
}
public ListNode insertFrontNode(ListNode a, int val) {
ListNode b = new ListNode(val);
b.next = a;
return b;
}
public void deleteNode(ListNode node) {
if (node == null) return;
node.val = node.next.val;
node.next = node.next.next;
}