Tonix - 博客园

HackerRank "Bike Racer"

摘要： Just for study from its editorial~Lesson learnt: an optimized Hungarian Algorithm: Hopcroft-Karp Algorithm (a batched version of Hungarian)A very good... 阅读全文

posted @ 2016-01-27 14:32 Tonix 阅读(332) 评论(0) 推荐(0)

LeetCode "Remove Duplicate Letters" !!

摘要： Interesting Greedy.. classichttps://leetcode.com/discuss/75529/c-simple-solution-easy-understandingclass Solution {public: string removeDuplicateLe... 阅读全文

posted @ 2016-01-27 07:47 Tonix 阅读(182) 评论(0) 推荐(0)

LeetCode "Count of Range Sum" !!

摘要： My naive Fenwick solution (value space) failed with the last test case in which there's INT_MIN\INT_MAX..So I learnt a smarter thought on Fenwick:http... 阅读全文

posted @ 2016-01-27 05:57 Tonix 阅读(205) 评论(0) 推荐(0)

LeetCode "Odd Even Linked List"

摘要： Visualize the unzip process.class Solution {public: ListNode* oddEvenList(ListNode* head) { if (!head || !head->next) return head; Li... 阅读全文

posted @ 2016-01-23 06:28 Tonix 阅读(198) 评论(0) 推荐(0)

LeetCode "Maximum Size Subarray Sum Equals k"

摘要： Nothing special. Point is, how clean can you do it?class Solution {public: int maxSubArrayLen(vector& nums, int k) { int n = nums.size()... 阅读全文

posted @ 2016-01-06 18:33 Tonix 阅读(162) 评论(0) 推荐(0)

LeetCode "Coin Change"

摘要： 1AC. Intuitive DP. But please note the if condition, there's a trick - we cannot build upon an invalid dp slot.class Solution {public: int coinChan... 阅读全文

posted @ 2016-01-06 18:29 Tonix 阅读(194) 评论(0) 推荐(0)

LeetCode "Shortest Distance from All Buildings"

摘要： Nothing magic here. Just BFS, but - BFS from land is not a good idea - BFS from Buildings.Lesson learnt: reverse thinking helps!class Solution {public... 阅读全文

posted @ 2015-12-22 07:22 Tonix 阅读(331) 评论(0) 推荐(0)

LeetCode "Bulb Switcher" !

摘要： https://leetcode.com/discuss/75014/math-solutionLesson learnt: dig deeper! 阅读全文

posted @ 2015-12-19 15:18 Tonix 阅读(158) 评论(0) 推荐(0)

LeetCode "Maximum Product of Word Lengths"

摘要： Another O(n^2) solution using bit ops. We prune 1/2(expected) candidates at each bit check.#define MAX_BITS 1600typedef bitset CandMask;class Solution... 阅读全文

posted @ 2015-12-17 04:16 Tonix 阅读(258) 评论(0) 推荐(0)

LeetCode "Burst Balloons" !!

摘要： What a classic DP problem..https://leetcode.com/discuss/72216/share-some-analysis-and-explanations 阅读全文

posted @ 2015-12-16 14:09 Tonix 阅读(148) 评论(0) 推荐(0)

LeetCode "Super Ugly Number" !

摘要： A classic type of problem: multi-pointer marching algorithm. For each pointer of each prime, we need to remember where it is in the ugly sequence, so ... 阅读全文

posted @ 2015-12-16 04:35 Tonix 阅读(186) 评论(0) 推荐(0)

LeetCode "Count of Smaller Number After Self"

摘要： Almost identical to LintCode "Count of Smaller Number before Self". Corner case needs to be taken care of.class Solution { ////////////////// //... 阅读全文

posted @ 2015-12-15 13:55 Tonix 阅读(172) 评论(0) 推荐(0)

LeetCode "Binary Tree Vertical Order"

摘要： BFS + HashTableclass Solution { int maxl, minl; unordered_map> hm;public: vector> verticalOrder(TreeNode* root) { maxl = INT_MIN; ... 阅读全文

posted @ 2015-12-15 12:26 Tonix 阅读(147) 评论(0) 推荐(0)

LeetCode "Sparse Matrix Multiplication"

摘要： Taking advantage of 'sparse'class Solution {public: vector> multiply(vector>& A, vector>& B) { vector> ret; int ha = A.si... 阅读全文

posted @ 2015-11-30 07:38 Tonix 阅读(444) 评论(0) 推荐(0)

LeetCode "Minimum Height Tree" !!

摘要： Simple data structure but not that easy to figure out.. MHT -> balanced tree.https://leetcode.com/problems/minimum-height-trees/Lesson learnt: Focus o... 阅读全文

posted @ 2015-11-26 16:02 Tonix 阅读(190) 评论(0) 推荐(0)

HackerRank "The Indian Job"

摘要： A sly knapsack problem in disguise! Thanks tohttps://github.com/bhajunsingh/programming-challanges/tree/master/hackerrank/algorithms/the-indian-jobLes... 阅读全文

posted @ 2015-11-26 08:44 Tonix 阅读(303) 评论(0) 推荐(0)

HackerRank "Poisonous Plants"

摘要： I had the same BFS idea as one of the AC code this: because dying pattern is spead from the initial dying ones :)#include #include #include using name... 阅读全文

posted @ 2015-11-26 07:10 Tonix 阅读(1005) 评论(0) 推荐(0)

HackerRank "Kundu and Tree" !!

摘要： Learnt from here:http://www.cnblogs.com/lautsie/p/3798165.htmlIdea is: we union all pure black edges so we get 1+ pure black edge groups. Then we can ... 阅读全文

posted @ 2015-11-26 03:51 Tonix 阅读(244) 评论(0) 推荐(0)

LeetCode "Best Time to Buy and Sell Stock with Cooldown" !

摘要： Very good DP one.First I figured out a O(n^2) solution:class Solution {public: int maxProfit(vector& prices) { int n = prices.si... 阅读全文

posted @ 2015-11-26 02:47 Tonix 阅读(247) 评论(0) 推荐(0)

HackerRank "AND xor OR"

摘要： Actually I think problem statement is somewhat misleading. No need to mention range [L, R] at all.The intention is a variation to "Largest Rectangle" ... 阅读全文

posted @ 2015-11-23 15:49 Tonix 阅读(249) 评论(0) 推荐(0)

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