lettuan

2017年1月5日

摘要： Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be 阅读全文

posted @ 2017-01-05 04:26 lettuan 阅读(251) 评论(0) 推荐(0)

Leetcode 40. Combination Sum II

摘要： Given a collection of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T. Each num 阅读全文

posted @ 2017-01-05 04:11 lettuan 阅读(148) 评论(0) 推荐(0)

Leetcode 39. Combination Sum

摘要： Given a set of candidate numbers (C) (without duplicates) and a target number (T), find all unique combinations in C where the candidate numbers sums 阅读全文

posted @ 2017-01-05 04:03 lettuan 阅读(424) 评论(0) 推荐(0)

Leetcode 230. Kth Smallest Element in a BST

摘要： Given a binary search tree, write a function kthSmallest to find the kth smallest element in it. Note: You may assume k is always valid, 1 ≤ k ≤ BST's 阅读全文

posted @ 2017-01-05 03:46 lettuan 阅读(109) 评论(0) 推荐(0)

2017年1月4日

Leetcode 144. Binary Tree Preorder Traversal

摘要：参考例子：[8,3,1,6,4,7,10,14,13] 8,3,1 和 6,4 说明从root开始，沿着左臂向下寻找leaf 的过程中应该逐个将node.val push入ans. 阅读全文

posted @ 2017-01-04 12:11 lettuan 阅读(115) 评论(0) 推荐(0)

Leetcode 94. Binary Tree Inorder Traversal

摘要： Given a binary tree, return the inorder traversal of its nodes' values. For example:Given binary tree [1,null,2,3], return [1,3,2]. 本题如果用recursive的方法非阅读全文

posted @ 2017-01-04 12:00 lettuan 阅读(92) 评论(0) 推荐(0)

Leetcode 285. Inorder Successor in BST

摘要： Given a binary search tree and a node in it, find the in-order successor of that node in the BST. 本题要求查找p在树中的inorder successor（中序遍历时的下一个节点）。根据p和root的关阅读全文

posted @ 2017-01-04 11:19 lettuan 阅读(140) 评论(0) 推荐(0)

Leetcode 255. Verify Preorder Sequence in Binary Search Tree

摘要：验证一个list是不是一个BST的preorder traversal sequence。 Given an array of numbers, verify whether it is the correct preorder traversal sequence of a binary sear 阅读全文

posted @ 2017-01-04 06:53 lettuan 阅读(494) 评论(0) 推荐(0)

Leetcode 270. Closest Binary Search Tree Value

摘要： Given a non-empty binary search tree and a target value, find the value in the BST that is closest to the target. Note: Given target value is a floati 阅读全文

posted @ 2017-01-04 05:47 lettuan 阅读(251) 评论(0) 推荐(0)

2017年1月2日

Leetcode 347. Top K Frequent Elements

摘要： Given a non-empty array of integers, return the k most frequent elements. For example,Given [1,1,1,2,2,3] and k = 2, return [1,2]. Note: You may assum 阅读全文

posted @ 2017-01-02 14:07 lettuan 阅读(108) 评论(0) 推荐(0)

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