# Count number of trailing zeros in Binary representation of a number using Bitset in C++

C++Server Side ProgrammingProgramming

Given an integer num as input. The goal is to find the number of trailing zeroes in the binary representation of num using bitset.

A bitset stores the bits 0s and 1s in it. It is an array of bits.

For Example

## Input

num = 10

## Output

Count of number of trailing zeros in Binary representation of a number using
Bitset are: 1

## Explanation

The number 10 in binary is represented as 1010 so trailing zeroes in it is
1.

## Input

num = 64

## Output

Count of number of trailing zeros in Binary representation of a number using Bitset are: 6

## Explanation

The number 64 in binary is represented as 10000000 so trailing zeroes in it is 6.

Approach used in the below program is as follows

In this approach we are using bitset. We will set the bitset with num using |. Now traverse bitset using for loop, as soon as the first 1 is encountered then break the loop otherwise increment count for trailing zeroes.

• Take an integer num as input.

• Function trailing_zeroes(int num) takes num and returns the count of number of trailing zeros in Binary representation of a number using Bitset.

• Take the initial count as 0.

• Take a bitset arr.

• Set it with num as arr |=num.

• Traverse arr using for loop from i=0 to i<64. If arr[i] is 0 then increment count else breaks the loop.

• Return count as result at the end of loop.

## Example

Live Demo

#include <bits/stdc++.h>
using namespace std;
int trailing_zeroes(int num){
int count = 0;
bitset<64> arr;
arr |= num;
for (int i = 0; i < 64; i++){
if (arr[i] == 0){
count++;
} else {
break;
}
}
return count;
}
int main(){
int num = 6;
cout<<"Count of number of trailing zeros in Binary representation of a number using Bitset are: "<<trailing_zeroes(num);
return 0;
}

## Output

If we run the above code it will generate the following output −

Count of number of trailing zeros in Binary representation of a number using Bitset are: 1