摘要：
X is a good number if after rotating each digit individually by 180 degrees, we get a valid number that is different from X. Each digit must be rotate 阅读全文
摘要：
A zero indexed array A consisting of N numbers is given. A slice of that array is any pair of integers (P, Q) such that 0 A = [1, 2, 3, 4] return: 3, 阅读全文