俩娃大妈在职刷题

楼主真棒，加油！

suhehe 发表于 2019/03/27 10:19:33


谢谢您的支持！在您的鼓励下，我今天一鼓作气刷了5道easy的题(^_^)，目前共刷了20题。洗洗睡了。明天早上6点半要起床给娃准备早餐，还有给晚餐备菜（要是我早上不把菜洗好切好，晚上来不及做饭给娃...

哈哈，共勉，昨天看完你的帖子就立马继续学Python了，效率也挺高的😁今天争取就把最后一个course的题刷完，一起加油呀，小姐姐。

再忙！也要打卡[Fist]
107. Binary Tree Level Order Traversal II
BFS: Runtime: 1 ms, faster than 88.42% of Java online submissions for Binary Tree Level Order Traversal II.
Memory Usage: 37.3 MB, less than 53.58% of Java online submissions for Binary Tree Level Order Traversal II.
DFS: Runtime: 1 ms, faster than 88.42% of Java online submissions for Binary Tree Level Order Traversal II.
Memory Usage: 37.2 MB, less than 75.87% of Java online submissions for Binary Tree Level Order Traversal II.  DFS比BFS省空间

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110. Balanced Binary Tree
还是用global variable的方法容易理解，以后再写不用global variable 的方法吧！Runtime: 1 ms, faster than 76.77% of Java online submissions for Balanced Binary Tree.
Memory Usage: 40.5 MB, less than 33.86% of Java online submissions for Balanced Binary Tree.

补充内容 (2019-3-29 11:11):
111. Minimum Depth of Binary Tree 晚上终于遇到一道稍微简单一点的题了
Runtime: 0 ms, faster than 100.00% of Java online submissions for Minimum Depth of Binary Tree.
Memory Usage: 39.8 MB, less than 12.17% of Java online submissions for Minimum Depth of Binary Tree.

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112. Path Sum recursion, 没什么好说的 Runtime: 0 ms, faster than 100.00% of Java online submissions for Path Sum.
Memory Usage: 38.7 MB, less than 34.72% of Java online submissions for Path Sum.

118. Pascal's Triangle
Runtime: 0 ms, faster than 100.00% of Java online submissions for Pascal's Triangle.
Memory Usage: 32.5 MB, less than 100.00% of Java online submissions for Pascal's Triangle.
说个八卦，刚才我码这道题的时候，刚上小学的老大看到了，说：“So easy！One plus one is easy work。”

补充内容 (2019-3-30 10:12):
119. Pascal's Triangle II
Runtime: 0 ms, faster than 100.00% of Java online submissions for Pascal's Triangle II.
Memory Usage: 32.5 MB, less than 100.00% of Java online submissions for Pascal's Triangle II.
我用的是recursion的方法。用DP的方法，我理解起来有困难。孩子啊！这题对你娘来说不容易呢！

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121. Best Time to Buy and Sell Stock 用DP的解法应该更快，但是我偷懒， 还是买低卖高的方法容易理解 Runtime: 1 ms, faster than 81.15% of Java online submissions for Best Time to Buy and Sell Stock.
Memory Usage: 39.6 MB, less than 30.47% of Java online submissions for Best Time to Buy and Sell Stock.

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122. Best Time to Buy and Sell Stock II
这道题好像出错了，没什么意思
Runtime: 1 ms, faster than 77.76% of Java online submissions for Best Time to Buy and Sell Stock II.
Memory Usage: 38.6 MB, less than 56.12% of Java online submissions for Best Time to Buy and Sell Stock II.

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125. Valid Palindrome 虽然我的解法慢了点，可是容易理解，算了！周末的晚上
Runtime: 6 ms, faster than 50.57% of Java online submissions for Valid Palindrome.
Memory Usage: 39.2 MB, less than 20.22% of Java online submissions for Valid Palindrome.

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136. Single Number 居然可以用XOR解！
Runtime: 0 ms, faster than 100.00% of Java online submissions for Single Number.
Memory Usage: 41.9 MB, less than 15.27% of Java online submissions for Single Number.

补充内容 (2019-3-30 12:04):
明天不用上班，今晚稍微晚点睡。但是不能太晚，因为娃早上8点要起来吃早餐了

补充内容 (2019-3-30 12:07):
目前共刷了34题了

141. Linked List Cycle 用双指针好理解：Runtime: 0 ms, faster than 100.00% of Java online submissions for Linked List Cycle.
Memory Usage: 37.5 MB, less than 96.73% of Java online submissions for Linked List Cycle.
Time complexity : O(n); Space complexity: O(1)。
然后还可以用Set， naive，太慢。Time complexity : O(n); Space complexity: O(1) 关键是新建一个Set也要花时间。所以只有Runtime: 5 ms, faster than 18.78% of Java online submissions for Linked List Cycle.
Memory Usage: 39.2 MB, less than 5.15% of Java online submissions for Linked List Cycle.

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155. Min Stack
我好怕写这些data structures。研究了一个最佳答案：Runtime: 45 ms, faster than 99.81% of Java online submissions for Min Stack.
Memory Usage: 38.3 MB, less than 92.96% of Java online submissions for Min Stack.

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157. Read N Characters Given Read4 题目好长，搞了半天才弄懂意思 Runtime: 0 ms, faster than 100.00% of Java online submissions for Read N Characters Given Read4.
Memory Usage: 35.8 MB, less than 43.80% of Java online submissions for Read N Characters Given Read4.
Time complexity : O(n); Space complexity: O(n)

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今天真累了。周末带娃比平时还累！又要买菜又要带娃去游乐场，平时正常的洗衣做饭一样不少，累死了！目前共刷37题

楼主小姐姐好棒！！！
收到了激励～努力刷题too！

160. Intersection of Two Linked Lists
看了一个小时也没搞懂最佳解法为什么设 a = a == null? headB : a.next; 今天周末，真是比平时更忙，因为带娃是从早上7点到晚上9点，没娃的人不能理解：-（ 而且我这一周oncall，进度不得不慢下来了。

好感动…

加油！！！！！！！！！娃一定也为你骄傲！

160. Intersection of Two Linked Lists
终于弄懂 a = a == null? headB : a.next; 的意思了，就是通过双链链接产生平头末端，这样在第二次iteration headB为首的List 和headA为首的List时候，这两条链肯定是尾端match的。Time complexity : O(m + n); Space complexity: O(1).

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167. Two Sum II - Input array is sorted
Two pointers。Runtime: 0 ms, faster than 100.00% of Java online submissions for Two Sum II - Input array is sorted.
Memory Usage: 38.5 MB, less than 24.19% of Java online submissions for Two Sum II - Input array is sorted.

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168. Excel Sheet Column Title 捣鼓了半天，没想到结果这么好！可是最佳答案只写一行，我写了if - else if - else
Runtime: 0 ms, faster than 100.00% of Java online submissions for Excel Sheet Column Title.
Memory Usage: 35.1 MB, less than 100.00% of Java online submissions for Excel Sheet Column Title.

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169. Majority Element
Moore Voting Algorithm, Time complexity: O(n) Space complexity: O(1)

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170. Two Sum III - Data structure design
不知道为什么，这道题总有case不能通过。算了，今晚on call，抓紧时间睡会，保佑今晚平平安安

补充内容 (2019-4-2 11:01):
目前刷了41题easy