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Algorithms, Distributed System, Machine Learning
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01 2017 档案

LeetCode "501. Find Mode in Binary Search Tree"
摘要：It is a matter of hashmap use. For the follow-up: 阅读全文
posted @ 2017-01-31 08:06 Tonix 阅读(151) 评论(0) 推荐(0)

LeetCode "483. Smallest Good Base" !!
摘要：A more programming-like solution, is to hack the problem from simple: we try each possble base value, and see which 111..11 fits target number - using 阅读全文
posted @ 2017-01-31 07:35 Tonix 阅读(279) 评论(0) 推荐(0)

LeetCode "467. Unique Substrings in Wraparound String" !!
摘要：Check out this brilliant solution:https://discuss.leetcode.com/topic/70658/concise-java-solution-using-dp My first solution was a O(n^2) typical DP bo 阅读全文
posted @ 2017-01-28 15:24 Tonix 阅读(105) 评论(0) 推荐(0)

LeetCode "437. Path Sum III"
摘要：The punch line of this one: sum of leaves: pi..pj = root..pj - root..pi. 阅读全文
posted @ 2017-01-28 14:44 Tonix 阅读(134) 评论(0) 推荐(0)

LeetCode "454. 4Sum II"
摘要：Split it into 2 group of arrays, 2 arrays in each group. Then use hashmap. class Solution { public: int fourSumCount(vector<int>& A, vector<int>& B, v 阅读全文
posted @ 2017-01-27 07:45 Tonix 阅读(168) 评论(0) 推荐(0)

LeetCode "445. Add Two Numbers II"
摘要：A natural stack based solution. Seriously, whey 'Medium'? /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * 阅读全文
posted @ 2017-01-27 06:21 Tonix 阅读(183) 评论(0) 推荐(0)

LeetCode "486. Predict the Winner" !!
摘要：Check this out: https://discuss.leetcode.com/topic/76312/java-1-line-recursion-solution Neat thoughts with neat code. Bravo. Deserve to learn. 阅读全文
posted @ 2017-01-26 14:48 Tonix 阅读(201) 评论(0) 推荐(0)

LeetCode "455. Assign Cookies"
摘要：Simple greedy thought .. satify each kid with minimum qualified cookie, from the least greedy kid.. 阅读全文
posted @ 2017-01-24 12:52 Tonix 阅读(175) 评论(0) 推荐(0)

LeetCode "492. Construct the Rectangle"
摘要：Idea is, among all factors of the int, we pick the two that is the closest pair. And searching from sqrt(area) is a better idea: https://discuss.leetc 阅读全文
posted @ 2017-01-24 11:05 Tonix 阅读(205) 评论(0) 推荐(0)

LeetCode "488. Zuma Game" !
摘要：I prefer shorter code, so this one:https://discuss.leetcode.com/topic/75448/memoization-c-solution Please note: we don't want to be too greedy - despe 阅读全文
posted @ 2017-01-22 12:08 Tonix 阅读(250) 评论(0) 推荐(0)

LeetCode "450. Delete Node in a BST"
摘要：Yes the most concise solution is recursion.https://discuss.leetcode.com/topic/66165/very-concise-c-solution-for-general-binary-tree-not-only-bst Here 阅读全文
posted @ 2017-01-21 15:35 Tonix 阅读(137) 评论(0) 推荐(0)

LeetCode "462. Minimum Moves to Equal Array Elements II"
摘要：Natural Greedy. Sort the array and pick the medium as target. 阅读全文
posted @ 2017-01-14 14:40 Tonix 阅读(103) 评论(0) 推荐(0)

LeetCode "Magical String"
摘要：Fun one. A matter of string generation by given rules. I know it can be much shorter.. but i'm lazy to do that. 阅读全文
posted @ 2017-01-14 13:50 Tonix 阅读(149) 评论(0) 推荐(0)

LeetCode "451. Sort Characters By Frequency"
摘要：Mediocre solution is O(nlgn) by using max-heap - but, remember bucket sort? it is O(n) 阅读全文
posted @ 2017-01-10 13:12 Tonix 阅读(99) 评论(0) 推荐(0)

LeetCode "475. Heaters"
摘要：This problem reflects a key strategy when dealing with discrete problem space - split split split.. That' is to say, we check each house and find its 阅读全文
posted @ 2017-01-09 14:20 Tonix 阅读(112) 评论(0) 推荐(0)

LeetCode "459. Repeated Substring Pattern"
摘要：Brutal force works - and a smarter way is to utilize KMP. The most popular two solutions are essentially the same - one is obvious KMP, and another on 阅读全文
posted @ 2017-01-08 09:26 Tonix 阅读(151) 评论(0) 推荐(0)

LeetCode "468. Validate IP Address"
摘要：it is all about corner-cases... 阅读全文
posted @ 2017-01-07 09:06 Tonix 阅读(174) 评论(0) 推荐(0)

LeetCode "473. Matchsticks to Square"
摘要：A trickier DFS, with a little bit complex recursion param tweak, and what's more important is pruning strategies.. or your code will TLE. 阅读全文
posted @ 2017-01-07 06:21 Tonix 阅读(167) 评论(0) 推荐(0)

LeetCode "477. Total Hamming Distance"
摘要：Fun one.. the punch line of this problem is quite common in Bit related problems on HackerRank - visualize it in your mind, and you will find: all bit 阅读全文
posted @ 2017-01-06 12:19 Tonix 阅读(112) 评论(0) 推荐(0)

LeetCode "448. Find All Numbers Disappeared in an Array"
摘要：My first reaction is to have an unlimited length of bit-array, to mark existence. But if no extra mem is allowed, we can simply use 'sign' on each ind 阅读全文
posted @ 2017-01-06 08:31 Tonix 阅读(119) 评论(0) 推荐(0)

LeetCode "419. Battleships in a Board"
摘要：The follow-up question is fun: "Could you do it in one-pass, using only O(1) extra memory and without modifying the value of the board?" When we meet 阅读全文
posted @ 2017-01-06 07:11 Tonix 阅读(139) 评论(0) 推荐(0)