俩娃大妈在职刷题

326. Power of Three
Time O(logn), Space O(1). Runtime: 10 ms, faster than 99.81% of Java online submissions for Power of Three.
Memory Usage: 34.5 MB, less than 100.00% of Java online submissions for Power of Three.

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342. Power of Four
Time O(logn), Space O(1). Runtime: 1 ms, faster than 81.60% of Java online submissions for Power of Four.
Memory Usage: 32.3 MB, less than 100.00% of Java online submissions for Power of Four. 下次再研究一下非loop version

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周末总是时间少，今天意思一下，累计easy 85题

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太励志了吧！向你学习！

344. Reverse String
Time O(n), Space O(1). Runtime: 1 ms, faster than 100.00% of Java online submissions for Reverse String.
Memory Usage: 51.2 MB, less than 5.01% of Java online submissions for Reverse String.

补充内容 (2019-4-15 12:04):
今天太晚了，明天再刷！

303. Range Sum Query - Immutable
用accumulative sum, NumArray(int[] nums) Time O(n), sumRange(int i, int j)  Time O(1). Runtime: 56 ms, faster than 67.19% of Java online submissions for Range Sum Query - Immutable.
Memory Usage: 42.3 MB, less than 50.00% of Java online submissions for Range Sum Query - Immutable.

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339. Nested List Weight Sum
DFS iterative: Time O(n), Space O(n) Runtime: 1 ms, faster than 84.71% of Java online submissions for Nested List Weight Sum.
Memory Usage: 35.8 MB, less than 82.82% of Java online submissions for Nested List Weight Sum. Recursion: Runtime: 0 ms, faster than 100.00% of Java online submissions for Nested List Weight Sum.
Memory Usage: 35.5 MB, less than 82.82% of Java online submissions for Nested List Weight Sum.

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345. Reverse Vowels of a String
two-pointer, Time O(n), Space O(n) Runtime: 4 ms, faster than 65.70% of Java online submissions for Reverse Vowels of a String.
Memory Usage: 40.2 MB, less than 25.63% of Java online submissions for Reverse Vowels of a String.

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目前刷89题。今天就这样了，后天早上有个业内大公司的recruiter电话，还是要稍微准备一下，很久没好好接个电话了

346. Moving Average from Data Stream
用queue，MovingAverage() Time O(1), Space O(1); next(), Time O(1), Space O(1)?
Runtime: 73 ms, faster than 59.64% of Java online submissions for Moving Average from Data Stream.
Memory Usage: 42.9 MB, less than 69.43% of Java online submissions for Moving Average from Data Stream.

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349. Intersection of Two Arrays
Using two sets. Time O(n), Space O(n+m). Runtime: 2 ms, faster than 97.57% of Java online submissions for Intersection of Two Arrays.
Memory Usage: 37.5 MB, less than 37.55% of Java online submissions for Intersection of Two Arrays.

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350. Intersection of Two Arrays II
把上题一个set 换成stack。Time O(n), Space O(n+m). Runtime: 3 ms, faster than 57.37% of Java online submissions for Intersection of Two Arrays II.
Memory Usage: 37.8 MB, less than 18.65% of Java online submissions for Intersection of Two Arrays II.

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今天就这样了。下面准备明天的电话！累计easy 92题

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目前AC率由最初的38%升高到40%。

367. Valid Perfect Square
Binary Search, Time O(log n), Space O(1). Note: we need to use long to store mid since we use mid * mid. Runtime: 0 ms, faster than 100.00% of Java online submissions for Valid Perfect Square.
Memory Usage: 31.7 MB, less than 100.00% of Java online submissions for Valid Perfect Square.

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374. Guess Number Higher or Lower
Binary Search, Time O(log n), Space O(1). Runtime: 0 ms, faster than 100.00% of Java online submissions for Guess Number Higher or Lower.
Memory Usage: 34.3 MB, less than 91.54% of Java online submissions for Guess Number Higher or Lower.

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404. Sum of Left Leaves
Recursion: Time O(n), Space O(1)? Runtime: 0 ms, faster than 100.00% of Java online submissions for Sum of Left Leaves.
Memory Usage: 38.8 MB, less than 5.30% of Java online submissions for Sum of Left Leaves.

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明天娃的班级组织去参观博物馆，早上6点钟要起床给娃准备午餐。今天就做到这里，easy 95题。

408. Valid Word Abbreviation
这个corner case "a" - "01" 太糟糕了！花了一个小时在这道题上。Time O(nm), Space O(n+m). Runtime: 1 ms, faster than 100.00% of Java online submissions for Valid Word Abbreviation.
Memory Usage: 36.7 MB, less than 88.09% of Java online submissions for Valid Word Abbreviation.

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409. Longest Palindrome
Time O(n), Space O(n), using Set. Runtime: 4 ms, faster than 88.24% of Java online submissions for Longest Palindrome.
Memory Usage: 36.8 MB, less than 32.21% of Java online submissions for Longest Palindrome. 但是看最佳解法，greedy居然更快！

补充内容 (2019-4-19 10:38):
今天就这样了，明天放假又要伺候娃了。easy 97题。最近好慢