刷题打卡 －pxu

463. Island Perimeter - dfs

842. Origami - lintcode: the length is actually Math.pow(2,n) + 1;

836. Rectangle Overlap:  if one is either left, or right, up or above the other, then, it's not overlapped

205. Isomorphic Strings: two maps or to hashing arrays

105. Construct Binary Tree from Preorder and Inorder Traversal. preorder array will provide root node and inorder array will get he node before it.

103. Binary Tree Zigzag Level Order Traversal: for list, used linkedlist instead of arraylist as it will do insert operation in the beginning of the list.

319. Bulb Switcher: math problem

楼主现在一共刷了多少道了啊？

michaelzju 发表于 2018-8-3 12:55
楼主现在一共刷了多少道了啊？

leetcode 224, lintcode 144, overall, it's about 250:)

47. Permutations II - make sure check nums[i] == nums[i-1] && !used[i-1]