**PROBLEM LINK:**

**Author:** rahul_ojha_07

**DIFFICULTY:**

CAKEWALK

**PREREQUISITES:**

Binary numbers,Bit Manipulation

**PROBLEM:**

Given the total number of biscuits Bruno ate, find the number of days he was active?

**QUICK EXPLANATION:**

Calculate the Binar form of the given Number and count the number of 1’s

**EXPLANATION:**

Since for each day the biscuits doubles up as the previous day with 1 biscuits on the first day, starting from i=0, the number of biscuits Bruno supposed to have on **i _{th}** day is

**2**

^{i}.

Only the days he was active he got biscuits. So adding the power of 2 on each day he was active, gives the total number of biscuits, i.e., N.

Hence, number of 1 in the binary representation of N is the number of days he was active.

**Author’s solution can be found here.**