question

We have a two dimensional matrix A where each value is 0 or 1.

A move consists of choosing any row or column, and toggling each value in that row or column: changing all 0s to 1s, and all 1s to 0s.

After making any number of moves, every row of this matrix is interpreted as a binary number, and the score of the matrix is the sum of these numbers.

Return the highest possible score.

question

Implement pow(x,n), which calculates x raised to the power n (i.e. xn).

question

Count the number of prime numbers less than a non-negative number, n.

本教程用的jdk9、IDEA3.2
如果觉得教程不够详细，可以看这个B站up主的视频：https://www.bilibili.com/video/BV1U7411z7ut?from=search&seid=5641378115535664960