immjc

摘要： Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowes 阅读全文

摘要： Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lowes 阅读全文

摘要： Given an unsorted array of integers, find the length of longest increasing subsequence. Example: Note: There may be more than one LIS combination, it 阅读全文

摘要： Given an integer n, count the total number of digit 1 appearing in all non-negative integers less than or equal to n. Example: Input: 13 Output: 6 Exp 阅读全文

摘要： Given a binary tree, flatten it to a linked list in-place. For example, given the following tree: 1 / \ 2 5 / \ \ 3 4 6 The flattened tree should look 阅读全文

摘要： Given a string, find the length of the longest substring without repeating characters. Examples: Given "abcabcbb", the answer is "abc", which the leng 阅读全文

摘要： Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Example: Input: [ 1->4->5, 1->3->4, 2->6 ] Output: 阅读全文

摘要： Given a collection of intervals, merge all overlapping intervals. Example 1: Input: [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explan 阅读全文

摘要： Sort a linked list using insertion sort. A graphical example of insertion sort. The partial sorted list (black) initially contains only the first elem 阅读全文

摘要： Sort a linked list in O(n log n) time using constant space complexity. Example 1: Input: 4->2->1->3 Output: 1->2->3->4 Example 2: Input: -1->5->3->4-> 阅读全文