Leetcode - 随笔分类(第10页) - neverlandly

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posted @ 2016-12-22 05:53 neverlandly 阅读(1705) 评论(0) 推荐(0)

Leetcode: Matchsticks to Square && Grammar: reverse an primative array

摘要：DFS, my solution is to fill each edge of the square one by one. DFS to construct the 1st, then 2nd, then 3rd, then 4th. For each edge I scan all the m 阅读全文

posted @ 2016-12-21 07:31 neverlandly 阅读(603) 评论(0) 推荐(0)

Leetcode: Serialize and Deserialize BST

摘要：So the first question is: what is the difference between this and #297? This here is BST, however, in #297, it's BT. "The encoded string should be as 阅读全文

posted @ 2016-12-21 04:44 neverlandly 阅读(752) 评论(0) 推荐(0)

Leetcode: Circular Array Loop

摘要：注意The loop must be "forward" or "backward'. 所以这就是为什么[-2, 1, -1, -2, -2]是false的原因 Just think it as finding a loop in Linkedlist, except that loops with 阅读全文

posted @ 2016-12-20 11:39 neverlandly 阅读(1539) 评论(0) 推荐(0)

Leetcode: Sequence Reconstruction

摘要：Topological Sort: This problem is to determine if there's one, and only one sequence to sort a DAG. The method is to check if the queue's size is alwa 阅读全文

posted @ 2016-12-20 07:15 neverlandly 阅读(968) 评论(0) 推荐(0)

Leetcode: Ternary Expression Parser

摘要：My First Solution: Use Stack and String operation, from the back of the string, find the first '?', push the right to stack. Depends on whether the ch 阅读全文

posted @ 2016-12-20 05:11 neverlandly 阅读(840) 评论(0) 推荐(0)

Leetcode: Word Squares && Summary: Another Important Implementation of Trie(Retrieve all the words with a given Prefix)

摘要：Backtracking + Trie: referred to https://discuss.leetcode.com/topic/63516/explained-my-java-solution-using-trie-126ms-16-16 A better approach is to ch 阅读全文

posted @ 2016-12-20 01:38 neverlandly 阅读(680) 评论(0) 推荐(0)

Leetcode: Ones and Zeroes

摘要：This is a 0/1 backpacking problem The problem can be interpreted as: What's the max number of str can we pick from strs with limitation of m "0"s and 阅读全文

posted @ 2016-12-19 13:32 neverlandly 阅读(485) 评论(0) 推荐(0)

Leetcode: Heaters

摘要：Binary Search My solution: Be careful in my binary search function, l, r may go out of the range of the array Solution with the highest vote: 阅读全文

posted @ 2016-12-19 13:09 neverlandly 阅读(464) 评论(0) 推荐(0)

Leetcode: Total Hamming Distance

摘要：Example: 0 0 0 0 0 1 0 0 1 1 1 0 0 0 1 0 Total Hamming Distance = (3*1) + (2*2) + (2*2) + (4*0) = 11 so the idea is count the number of 1 and 0 on eac 阅读全文

posted @ 2016-12-19 11:03 neverlandly 阅读(952) 评论(0) 推荐(0)

Leetcode: Hamming Distance

摘要：Solution 1: Solution 2: 阅读全文

posted @ 2016-12-19 09:17 neverlandly 阅读(234) 评论(0) 推荐(0)

Leetcode: Valid Word Square

摘要：这题看起来简单但是其实很容易写错本来想j 不从0开始，而是从 i+1开始检查，可以节省时间，但是一些为Null的情况会使讨论很复杂比如阅读全文

posted @ 2016-12-19 08:37 neverlandly 阅读(291) 评论(0) 推荐(0)

Leetcode: Sentence Screen Fitting

摘要：先来一个brute force, 类似Text Adjustment 但是在稍微大一点的case就TLE了，比如： ["a","b","e"] 20000 20000，花了465ms 所以想想怎么节约时间，提示是可以DP的，想想怎么复用，refer to: https://discuss.lee 阅读全文

posted @ 2016-12-19 07:16 neverlandly 阅读(1135) 评论(0) 推荐(0)

Leetcode: Minimum Unique Word Abbreviation

摘要：Refer to https://discuss.leetcode.com/topic/61799/java-bit-mask-dfs-with-pruning bit mask refer to http://bookshadow.com/weblog/2016/10/02/leetcode-mi 阅读全文

posted @ 2016-12-19 04:47 neverlandly 阅读(885) 评论(0) 推荐(0)

Leetcode: Design Phone Directory

摘要：my HashSet+ ArrayList, 删除的时候把要删的index与末尾对调。get()其实不需要random, 因为anyone is ok HashSet+ Queue网上vote最高的solution, 阅读全文

posted @ 2016-12-18 13:37 neverlandly 阅读(340) 评论(0) 推荐(0)

Leetcode: Valid Word Abbreviation

摘要：Given a non-empty string s and an abbreviation abbr, return whether the string matches with the given abbreviation. A string such as "word" contains only the following valid abbreviations: ["word",... 阅读全文

posted @ 2016-12-18 12:49 neverlandly 阅读(529) 评论(0) 推荐(0)

Leetcode: Range Addition

摘要：Time Complexity: O(N+K), Space: O(1) 阅读全文

posted @ 2016-12-18 11:49 neverlandly 阅读(332) 评论(0) 推荐(0)

Leetcode: Find Leaves of Binary Tree

摘要：Better Solution: https://discuss.leetcode.com/topic/49194/10-lines-simple-java-solution-using-recursion-with-explanation/2 For this question we need t 阅读全文

posted @ 2016-12-18 09:12 neverlandly 阅读(296) 评论(0) 推荐(0)

Leetcode: Design Hit Counter

摘要：Use Queue Better Solution: can solve follow up, refer to https://discuss.leetcode.com/topic/48758/super-easy-design-o-1-hit-o-s-gethits-no-fancy-data- 阅读全文

posted @ 2016-12-18 07:56 neverlandly 阅读(722) 评论(0) 推荐(0)

Leetcode: Bomb Enemy

摘要：Walk through the matrix. At the start of each non-wall-streak (row-wise or column-wise), count the number of hits in that streak and remember it. For 阅读全文

posted @ 2016-12-18 06:52 neverlandly 阅读(499) 评论(0) 推荐(0)

随笔分类 - Leetcode