俩娃大妈在职刷题

awesome, you take care of two kids, still study hard, I admire you

赞一个！

cybermerman 发表于 2019/04/02 09:44:33
awesome, you take care of two kids, still study hard, I admire you

谢谢！因为太想跳出现在的环境了。前两天炒菜的时候，听见老二在自娱自乐地编故事：“国王今天上夜班。。。” 我觉得又好笑又无可奈何，她爸影响了她对国王的认知。

很励志！加油鸭！

170. Two Sum III - Data structure design
昨晚做到最后太累了，看不出原因。现在一看，就知道自己的if语句没写清楚。HashMap 结构。add(int number) time comlexcity: O(1); find(int number) time comlexcity: O(n).

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171. Excel Sheet Column Number
Time complexity: O(n), Space complexity: O(1)

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172. Factorial Trailing Zeroes
Runtime: 0 ms, faster than 100.00% of Java online submissions for Factorial Trailing Zeroes.
Memory Usage: 32.1 MB, less than 100.00% of Java online submissions for Factorial Trailing Zeroes. Time complexity: O(log n), Space complexity: O(1)

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175. Combine Two Tables
Runtime: 228 ms, faster than 32.44% of MySQL online submissions for Combine Two Tables.
我只会Postgresql，面试一定要用MySQL吗？

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176. Second Highest Salary
Runtime: 127 ms, faster than 86.05% of MySQL online submissions for Second Highest Salary.

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目前刷了easy 46题

今晚10点钟才开始做题，就是为了“不叫一日闲过”，虽然我也没闲过。
181. Employees Earning More Than Their Managers
Runtime: 287 ms, faster than 93.65% of MySQL online submissions for Employees Earning More Than Their Managers.

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182. Duplicate Emails
HAVING语句 Runtime: 190 ms, faster than 74.08% of MySQL online submissions for Duplicate Emails.

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183. Customers Who Never Order
NOT IN 语句 Runtime: 272 ms, faster than 38.11% of MySQL online submissions for Customers Who Never Order.

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189. Rotate Array
三次reverse，Time complexity: O(n), Space complexity: O(1)

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目前共刷easy 50道题。今天累坏了，待会还要看看oncall的情况。

姐姐优秀!向姐姐学习~

196. Delete Duplicate Emails
DELETE + INNER JOIN
Runtime: 718 ms, faster than 71.95% of MySQL online submissions for Delete Duplicate Emails.

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197. Rising Temperature
TO_DAYS()
Runtime: 325 ms, faster than 72.78% of MySQL online submissions for Rising Temperature.

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198. House Robber
又是DP，忽然对DP有点感觉了，好像就是fibonacci number的变体。Time complexity: O(n), Space complexity: O(1).
Runtime: 0 ms, faster than 100.00% of Java online submissions for House Robber.
Memory Usage: 35.6 MB, less than 92.14% of Java online submissions for House Robber.

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下面看位运算，争取尽早完成190 和191两题

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190. Reverse Bits
原数bit右移，result 左移
Runtime: 1 ms, faster than 100.00% of Java online submissions for Reverse Bits.
Memory Usage: 27.8 MB, less than 96.31% of Java online submissions for Reverse Bits.

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191. Number of 1 Bits
Runtime: 0 ms, faster than 100.00% of Java online submissions for Number of 1 Bits.
Memory Usage: 32.2 MB, less than 100.00% of Java online submissions for Number of 1 Bits.
目前累计刷easy 55题

202. Happy Number
Time Complexity: O(n), Space Coomlexity: O(1) Runtime: 1 ms, faster than 86.65% of Java online submissions for Happy Number.
Memory Usage: 32.3 MB, less than 100.00% of Java online submissions for Happy Number.

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203. Remove Linked List Elements
Time Complexity: O(n), Space Coomlexity: O(1)  Runtime: 1 ms, faster than 99.86% of Java online submissions for Remove Linked List Elements.
Memory Usage: 40.5 MB, less than 86.86% of Java online submissions for Remove Linked List Elements.

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204. Count Primes Time Complexity: O(n^2), Space Coomlexity: O(n)
Runtime: 12 ms, faster than 82.25% of Java online submissions for Count Primes.
Memory Usage: 33 MB, less than 100.00% of Java online submissions for Count Primes.

今天周末，老公在ICU上24小时班。一个人带娃，上午买菜，下午带娃打网球，晚上大清洗。让我哭哭就好。坚持刷题一道！206. Reverse Linked List
经典题，就是我还不熟。Runtime: 0 ms, faster than 100.00% of Java online submissions for Reverse Linked List.
Memory Usage: 37.7 MB, less than 46.81% of Java online submissions for Reverse Linked List.

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217. Contains Duplicate
1）先sort array，再找重复数据，找到就是true，否则是false；Time Complexity: O(nlgn), Space Complexity: O(1);
Runtime: 5 ms, faster than 94.44% of Java online submissions for Contains Duplicate.
Memory Usage: 43.4 MB, less than 15.54% of Java online submissions for Contains Duplicate. 2）用set，Time Complexity: O(n), Space Complexity: O(1)
Runtime: 10 ms, faster than 32.87% of Java online submissions for Contains Duplicate.
Memory Usage: 44.7 MB, less than 5.03% of Java online submissions for Contains Duplicate. 为什么用set 跑起来更慢？

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219. Contains Duplicate II
用Map: Time Complexity: O(n), Space Complexity: O(1) Runtime: 9 ms, faster than 53.88% of Java online submissions for Contains Duplicate II.
Memory Usage: 44.4 MB, less than 21.94% of Java online submissions for Contains Duplicate II. 看了一下，优化后还可以用Set，更快：Runtime: 7 ms, faster than 90.79% of Java online submissions for Contains Duplicate II.
Memory Usage: 44.5 MB, less than 17.38% of Java online submissions for Contains Duplicate II. 怎么看起来还是Time Complexity: O(n), Space Complexity: O(1)

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目前刷了61道easy。洗洗睡了，做不完的只能等明天了。谁叫我是负重前行的人呢？明天开车不能出事。