11 2015 档案

[LeetCode] Range Sum Query - Mutable
摘要：This problem requires a new data structure --- Segment Tree. You may use this GeeksforGeeks article to get some ideas of it. However, the code in this... 阅读全文
posted @ 2015-11-23 17:14 jianchao-li 阅读(1497) 评论(0) 推荐(0) 编辑
[LeetCode] Additive Number
摘要：Af first I read the title as "Addictive Number". Anyway, this problem can be solved elegantly using recursion. This post shares a nice recursive C++ c... 阅读全文
posted @ 2015-11-20 13:16 jianchao-li 阅读(862) 评论(0) 推荐(0) 编辑
[LeetCode] Number of Islands II
摘要：Problem Description:A 2d grid map ofmrows andncolumns is initially filled with water. We may perform anaddLandoperation which turns the water at posit... 阅读全文
posted @ 2015-11-14 20:55 jianchao-li 阅读(7298) 评论(0) 推荐(0) 编辑
[LeetCode] Range Sum Query 2D - Immutable
摘要：Very similar to Range Sum Query - Immutable, but we now need to compute a 2d accunulated-sum. In fact, if you work in computer vision, you may know a ... 阅读全文
posted @ 2015-11-12 22:00 jianchao-li 阅读(668) 评论(0) 推荐(0) 编辑
[LeetCode] Range Sum Query - Immutable
摘要：The idea is fairly straightforward: create an arrayaccuthat stores the accumulated sum fornumssuch thataccu[i] = nums[0] + ... + nums[i]in the initial... 阅读全文
posted @ 2015-11-10 13:43 jianchao-li 阅读(989) 评论(0) 推荐(0) 编辑
[LeetCode] Smallest Rectangle Enclosing Black Pixels
摘要：This post shares very detailed explanation of how to use binary search to find the boundaries of the smallest rectangle that encloses the black pixels... 阅读全文
posted @ 2015-11-08 21:00 jianchao-li 阅读(1280) 评论(0) 推荐(0) 编辑
[LeetCode] Remove Invalid Parentheses
摘要：This problem can be solved very elegantly using BFS, as in this post.The code is rewritten below in C++. 1 class Solution { 2 public: 3 vector rem... 阅读全文
posted @ 2015-11-05 15:38 jianchao-li 阅读(1429) 评论(0) 推荐(0) 编辑
[LeetCode] Longest Increasing Subsequence
摘要：A typical O(n^2) solution uses dynamic programming. Let's use lens[j] to denote the length of the LIS ending with nums[j]. The state equations arelens... 阅读全文
posted @ 2015-11-03 22:15 jianchao-li 阅读(404) 评论(1) 推荐(0) 编辑