俩娃大妈在职刷题

15. 3Sum
Two pointers, Time O(n^2), Space O(1). Runtime: 29 ms, faster than 95.40% of Java online submissions for 3Sum.
Memory Usage: 46.3 MB, less than 95.67% of Java online submissions for 3Sum.

补充内容 (2019-5-9 10:41):
16. 3Sum Closest
Two pointers, Time O(n^2), Space O(1). Runtime: 4 ms, faster than 98.41% of Java online submissions for 3Sum Closest.
Memory Usage: 35.9 MB, less than 97.23% of Java online submissions for 3Sum Closest.

加油，当妈妈不容易，尤其是两个娃。希望你早日拿到500k大包裹。

airbots 发表于 2019/05/10 06:38:43
加油，当妈妈不容易，尤其是两个娃。希望你早日拿到500k大包裹。

我要是年薪10万，我都不跳槽了。哭死～

加油加油 刷起来刷起来！ 我都刷到走火入魔啦！

17. Letter Combinations of a Phone Number
Backtrack(DFS?), Time O(3^N * 4^M), Space O(3^N * 4^M).
Runtime: 0 ms, faster than 100.00% of Java online submissions for Letter Combinations of a Phone Number.
Memory Usage: 35.2 MB, less than 89.39% of Java online submissions for Letter Combinations of a Phone Number.

补充内容 (2019-5-10 20:32):
Easy 101, medium 14

18. 4Sum
Time O(n*n*Two-pointer-O(n)) = O(n^3), Space O(n). 本来不难的题，跟了一个misleading 的mostly voted 的解法，折腾了两个小时还是跟另一个人的解法解出来。
Runtime: 11 ms, faster than 90.88% of Java online submissions for 4Sum.
Memory Usage: 36.4 MB, less than 98.70% of Java online submissions for 4Sum.

补充内容 (2019-5-12 00:43):
Easy 101, medium 15

加油，很厉害，同在职妈妈我最慢，一礼拜只刷了9道，像你们学习

又在职 又刷题 想着都累 头疼心跳

19. Remove Nth Node From End of List
Two-pointer, time O(n), Space O(1).
Runtime: 0 ms, faster than 100.00% of Java online submissions for Remove Nth Node From End of List.
Memory Usage: 33.8 MB, less than 100.00% of Java online submissions for Remove Nth Node From End of List.
可是我还是不懂为什么假设dummy move两次，最后还是return dummy.next?

补充内容 (2019-5-12 11:03):
Easy 101, medium 16

Sujievic 发表于 2019/05/11 16:18:44
加油，很厉害，同在职妈妈我最慢，一礼拜只刷了9道，像你们学习

谢谢！我这星期也是只刷9题。到medium难度，我的速度马上慢下来了。