qiyuangong / Google_APAC

My solution for Google APAC

Notice:

1. Larger dataset only have one chance, and it will expire in 4 minutes. So make sure your code is correct and efficient before submit larger dataset.

2. Some times Google requires you to mod 1000000007 to avoid long result.

2016 A Round

#	Title	Solution	Basic idea (One line)
B	gcube	Python

2017 Pactice

#	Title	Solution	Basic idea (One line)
A	Lazy Spelling Bee	Python	\prod_{i=0}^{n - 1} len(set(i - 1, i, i + 1))
B	Robot Rock Band	Python

2017 A Round

#	Title	Solution	Basic idea (One line)
A	Country Leader	Python	String slicing and sort
B	Rain	Python
C	Jane's Flower Shop	Python	Binary search on double
D	Clash Royale	Python

2017 B Round

#	Title	Solution	Basic idea (One line)
A	Sherlock and Parentheses	Python	(n + 1) * n / 2
B	Sherlock and Watson Gym Secrets	Python	Three optimizations: 1. Fast power(x, y) % n 2. 0~k-1 buckets 3. (i + k)^A % k == i^A % k, so if i satisfies, then i + k, i + 2k.... satisfy condition.
C	Watson and Intervals	Python	l and r interval problem, sort and computer count (add on l, subtract on r). When count == 1, it is a unique interval for current interval.
D	Sherlock and Permutation Sorting	Python	f(n) = n! - \sum f(i)*(n- i)!, then optimize dp from O(n^3) to O(n^2)