Leetcode#105. Construct Binary Tree from Preorder and Inorder Traversal
ProblemGiven two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the same tree, construct and return the binary tree.
Example 1:
!https://assets.leetcode.com/uploads/2021/02/19/tree.jpg
123Input: preorder = [3,9,20,15,7], inorder = [9,3,15,20,7]Output: [3,9,20,null,null,15,7]
Example 2:
123Input: preorder = [-1], inorder = [-1]Output: [-1]
Constraints:
1 <= preorder.length <= 3000
inorder.length == pr ...
Leetcode#149. Max Points on a Line
ProblemGiven an array of points where points[i] = [xi, yi] represents a point on the X-Y plane, return the maximum number of points that lie on the same straight line.
Example 1:
!https://assets.leetcode.com/uploads/2021/02/25/plane1.jpg
123Input: points = [[1,1],[2,2],[3,3]]Output: 3
Example 2:
!https://assets.leetcode.com/uploads/2021/02/25/plane2.jpg
123Input: points = [[1,1],[3,2],[5,3],[4,1],[2,3],[1,4]]Output: 4
Constraints:
1 <= points.length <= 300
points[i].length == 2
10^4 & ...
Leetcode#146. LRU Cache
ProblemDesign a data structure that follows the constraints of a Least Recently Used (LRU) cache.
Implement the LRUCache class:
LRUCache(int capacity) Initialize the LRU cache with positive size capacity.
int get(int key) Return the value of the key if the key exists, otherwise return 1.
void put(int key, int value) Update the value of the key if the key exists. Otherwise, add the key-value pair to the cache. If the number of keys exceeds the capacity from this operation, evict the least recent ...