testseries

Question

Data structure for loop.  What is oxf ? can somebody explain

Answer 1

Let's take n = 17

$17_{10} = (10001)_{2}$

$count = 0$

 $(0xf)_{16} = (15)_{10} =(1111)_{2} $

$for(n; n > 0; n>>4)$

$count = count + table[ 17 & 15 ]  = count + table[1] = 0 + 1 = 1$

$n >> 4$ means right shift by 4 bits

$17 >> 4$ = 1

$count = count + table[1 & 15] =  1 + table[1] = 1 + 1 = 2$

$1 >> 4$ = 0 , loop will be terminated;

$count = 2$

Here we can see that there are 2 1's in the binary representation of $17$ 

Comments

thank you pankaj for such detailed explaination