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Codeforces #1113C
1113C C. Sasha and a Bit of Relax 题意 给一个数组，然后求满足 的[l, r]子序列有多少个，其中表示异或计算。 思路 关键点在于如果满足条件的[l,r]存在，那么
Logistic Regression
逻辑斯谛回归因为其易于实现，可解释性强，已经成为了工业界应用最广泛的机器学习算法。这篇文章主要讨论的是二项逻辑斯谛回归 (binominal logistic regression)，以下简称LR。
POJ3020
POJ3020 Antenna Placement Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 10821 Accepted: 5324 Description The Global Aerial Research Centre has been allotted the task of building the fifth generation of mobile phone nets in Sweden. The most striking reason why they got the job, is their discovery of a new, highly noise resistant, antenna. It is called 4DAir, and comes in four types. Each type can only transmit and receive signals in a direction aligned with a (slightly skewed) latitudinal and longitudinal grid, because of the interacting electromagnetic field of the earth. The four types correspond to antennas operating in the directions north, west, south, and east, respectively. Below is an example picture of places of interest, depicted by twelve small rings, and nine 4DAir antennas depicted by ellipses covering them.