power function by bitwise operations

[maitrasagnik]

can anyone tell me how to implement the function to calculate power of 2 with the help of bitwise operations.

 

[QwertyManiac]

Left shift operator is all you need.

To calculate 2^n, do:

2<<(n-1)

n-1 cause 2<<0 is 2 itself.

Some examples:

[B](2 squared)[/B]
2<<1
4

[B](2 cubed)[/B]
2<<2
8

[B](2^4)[/B]
2<<3
16

[B](2^1)[/B]
2<<0
2

[B](2^11)[/B]
2<<10
2048

 

[maitrasagnik]

thnxxx qm.

 

[manubatham20]

Can the power of any other number calculated through it.

 

[QwertyManiac]

No, it works out only for 2^n. For a^n there are other ways but none as efficient as this ..