C 位数组 （Bitarray）

1.设置

#define SetBit(A,k)     ( A[(k/32)] |= (1 << (k%32)) )   

2.清除

#define ClearBit(A,k)   ( A[(k/32)] &= ~(1 << (k%32)) ) 

3.测试

#define TestBit(A,k)    ( A[(k/32)] & (1 << (k%32)) )

参考：

http://www.mathcs.emory.edu/~cheung/Courses/255/Syllabus/1-C-intro/bit-array.html

https://stackoverflow.com/questions/4201301/warning-left-shift-count-width-of-type

https://en.wikipedia.org/wiki/Bit_array

https://michaeldipperstein.github.io/bitarray.html

https://www.codeproject.com/Tips/53433/BitArray-in-C