Batch add 1 solutions: 1206.design-skiplist...

1206.design-skiplist.java

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+#
+# @lc app=leetcode id=1206 lang=java
+#
+# [1206] Design Skiplist
+#
+# @lc code=start
+import java.util.Random;
+
+class Skiplist {
+    static final int MAX_LEVEL = 16;
+    static final double P = 0.5;
+    final Node head = new Node(-1, MAX_LEVEL);
+    int level = 1;
+    Random rand = new Random();
+
+    static class Node {
+        int val;
+        Node[] forward;
+        Node(int val, int level) {
+            this.val = val;
+            this.forward = new Node[level];
+        }
+    }
+
+    public Skiplist() {}
+
+    private int randomLevel() {
+        int lvl = 1;
+        while (lvl < MAX_LEVEL && rand.nextDouble() < P) {
+            lvl++;
+        }
+        return lvl;
+    }
+
+    public boolean search(int target) {
+        Node curr = head;
+        for (int i = level - 1; i >= 0; --i) {
+            while (curr.forward[i] != null && curr.forward[i].val < target) {
+                curr = curr.forward[i];
+            }
+        }
+        curr = curr.forward[0];
+        return curr != null && curr.val == target;
+    }
+
+    public void add(int num) {
+        Node[] update = new Node[MAX_LEVEL];
+        Node curr = head;
+        for (int i = level - 1; i >= 0; --i) {
+            while (curr.forward[i] != null && curr.forward[i].val < num) {
+                curr = curr.forward[i];
+            }
+            update[i] = curr;
+        }
+        int lvl = randomLevel();
+        if (lvl > level) {
+            for (int i = level; i < lvl; ++i) {
+                update[i] = head;
+            }
+            level = lvl;
+        }
+        Node newNode = new Node(num, lvl);
+        for (int i = 0; i < lvl; ++i) {
+            newNode.forward[i] = update[i].forward[i];
+            update[i].forward[i] = newNode;
+        }
+    }
+
+    public boolean erase(int num) {
+        Node[] update = new Node[MAX_LEVEL];
+        Node curr = head;
+        for (int i = level - 1; i >= 0; --i) {
+            while (curr.forward[i] != null && curr.forward[i].val < num) {
+                curr = curr.forward[i];
+            }
+            update[i] = curr;
+        }
+        curr = curr.forward[0];
+        if (curr == null || curr.val != num) return false;
+        for (int i = 0; i < level; ++i) {
+            if (update[i].forward[i] != curr) break;
+            update[i].forward[i] = curr.forward[i];
+        }
+        while (level > 1 && head.forward[level - 1] == null) {
+            level--;
+        }
+        return true;
+    }
+}
+
+/**
+* Your Skiplist object will be instantiated and called as such:
+* Skiplist obj = new Skiplist();
+* boolean param_1 = obj.search(target);
+* obj.add(num);
+* boolean param_3 = obj.erase(num);
+*/
+# @lc code=end

1367.linked-list-in-binary-tree.java

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+#
+# @lc app=leetcode id=1367 lang=java
+#
+# [1367] Linked List in Binary Tree
+#
+# @lc code=start
+/**
+* Definition for singly-linked list.
+* public class ListNode {
+*     int val;
+*     ListNode next;
+*     ListNode() {}
+*     ListNode(int val) { this.val = val; }
+*     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+* }
+*/
+/**
+* Definition for a binary tree node.
+* public class TreeNode {
+*     int val;
+*     TreeNode left;
+*     TreeNode right;
+*     TreeNode() {}
+*     TreeNode(int val) { this.val = val; }
+*     TreeNode(int val, TreeNode left, TreeNode right) {
+*         this.val = val;
+*         this.left = left;
+*         this.right = right;
+*     }
+* }
+*/
+class Solution {
+    public boolean isSubPath(ListNode head, TreeNode root) {
+        if (root == null) return false;
+        if (checkPath(head, root)) return true;
+        return isSubPath(head, root.left) || isSubPath(head, root.right);
+    }
+    private boolean checkPath(ListNode head, TreeNode node) {
+        if (head == null) return true;
+        if (node == null) return false;
+        if (head.val != node.val) return false;
+        return checkPath(head.next, node.left) || checkPath(head.next, node.right);
+    }
+}
+# @lc code=end