Count Trailing Zeros in Binary Representation of a Number Using Bitset in C++

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