100  
101  
---  
100  
100  
101  
---  
101  
100  
101  
---  
001  
101 
---  
010  
0001_0111 >> 3 = 0000_0010
0001_0111 << 3 = 1011_1000
x << k
Example: 5 * 8 = 5 << 3
x >> k
Example: 20 / 16 = 20 >> 4
x & (2k-1)
Example: 20 % 16 = 20 & 15
(x != 0) && (x & (x - 1)) == 0