Count total bits in a number
Last Updated :
15 Jul, 2022
Given a positive number n, count total bit in it.
Examples:
Input : 13
Output : 4
Binary representation of 13 is 1101
Input : 183
Output : 8
Input : 4096
Output : 13
Method 1 (Using Log)
The log2(n) logarithm in base 2 of n, which is the exponent to which 2 is raised to get n only integer and we add 1 find total bit in a number in log(n) time.
C++
// C++ program to find total bit in given number
#include <iostream>
#include <cmath>
unsigned countBits(unsigned int number)
{
// log function in base 2
// take only integer part
return (int)log2(number)+1;
}
// Driven program
int main()
{
unsigned int num = 65;
std::cout<<countBits(num)<<'\n';
return 0;
}
// This code is contributed by thedev05.
// C program to find total bit in given number
#include <stdio.h>
#include <math.h>
unsigned countBits(unsigned int number)
{
// log function in base 2
// take only integer part
return (int)log2(number)+1;
}
// Driven program
int main()
{
unsigned int num = 65;
printf("%d\n", countBits(num));
return 0;
}
// Java program to
// find total bit
// in given number
import java.io.*;
class GFG
{
static int countBits(int number)
{
// log function in base 2
// take only integer part
return (int)(Math.log(number) /
Math.log(2) + 1);
}
// Driver code
public static void main (String[] args)
{
int num = 65;
System.out.println(countBits(num));
}
}
// This code is contributed by vij
# Python3 program to find
# total bit in given number
import math
def countBits(number):
# log function in base 2
# take only integer part
return int((math.log(number) /
math.log(2)) + 1);
# Driver Code
num = 65;
print(countBits(num));
# This code is contributed by mits
// C# program to find total bit
// in given number
using System;
class GFG {
static uint countBits(uint number)
{
// log function in base 2
// take only integer part
return (uint)Math.Log(number , 2.0) + 1;
}
// Driver code
public static void Main()
{
uint num = 65;
Console.WriteLine(countBits(num));
}
}
// This code is contributed by Sam007.
<?php
// PHP program to find total
// bit in given number
function countBits($number)
{
// log function in base 2
// take only integer part
return (int)(log($number) /
log(2)) + 1;
}
// Driver Code
$num = 65;
echo(countBits($num));
// This code is contributed by Ajit.
?>
<script>
// JavaScript program to find total bit in given number
function countBits(number) {
// log function in base 2
// take only integer part
return Math.floor(Math.log2(number)+1);
}
// Driven program
let num = 65;
document.write(countBits(num));
// This code is contributed by Surbhi Tyagi
</script>
Time Complexity : O(logn)
Auxiliary Space : O(1)
Method 2 (Using Bit Traversal)
C
/* Function to get no of bits in binary
representation of positive integer */
#include <stdio.h>
unsigned int countBits(unsigned int n)
{
unsigned int count = 0;
while (n)
{
count++;
n >>= 1;
}
return count;
}
/* Driver program*/
int main()
{
int i = 65;
printf("%d", countBits(i));
return 0;
}
/* Function to get no of bits in binary
representation of positive integer */
class GFG {
static int countBits(int n)
{
int count = 0;
while (n != 0)
{
count++;
n >>= 1;
}
return count;
}
/* Driver program*/
public static void main(String[] arg)
{
int i = 65;
System.out.print(countBits(i));
}
}
// This code is contributed by Smitha.
# Function to get no of bits
# in binary representation
# of positive integer
def countBits(n):
count = 0
while (n):
count += 1
n >>= 1
return count
# Driver program
i = 65
print(countBits(i))
# This code is contributed
# by Smitha
/* Function to get no of bits
in binary representation of
positive integer */
using System;
class GFG
{
static int countBits(int n)
{
int count = 0;
while (n != 0)
{
count++;
n >>= 1;
}
return count;
}
// Driver Code
static public void Main ()
{
int i = 65;
Console.Write(countBits(i));
}
}
// This code is contributed
// by akt_mit.
<?php
// PHP Code to get no of bits in binary
// representation of positive integer
// Function to get no of bits in binary
// representation of positive integer
function countBits($n)
{
$count = 0;
while ($n)
{
$count++;
$n >>= 1;
}
return $count;
}
// Driver Code
$i = 65;
echo(countBits($i));
// This code is contributed by Ajit.
?>
<script>
/* Function to get no of bits
in binary representation of
positive integer */
function countBits(n)
{
var count = 0;
while (n != 0)
{
count++;
n >>= 1;
}
return count;
}
// Driver Code
var i = 65;
document.write(countBits(i));
</script>
Time Complexity : O(logn)
Auxiliary Space : O(1)
Method 3 ( Using conversion from binary to string)
C++
// C++ program to implement the approach
#include <bits/stdc++.h>
using namespace std;
// function to count the number of bits in a number n
int count_bits(int n)
{
// to_string() returns the binary string
// representation of the number n
string binary = bitset< 64 >(n).to_string();
// returning the length of the binary string
return 64 - binary.find('1');
}
int main()
{
int a = 65;
int b = 183;
cout << "Total bits in " << a << " : " << count_bits(a) << endl;
cout << "Total bits in " << b << " : " << count_bits(b) << endl;
}
// This code is contributed by phasing17
// Java code to implement the approach
class GFG {
// function to count the number of bits in a number n
static int count_bits(int n)
{
// return the length of the binary string
return Integer.toBinaryString(n).length();
}
// Driver Code
public static void main(String[] args)
{
int a = 65;
int b = 183;
// function call
System.out.printf("Total bits in %d: %d\n", a,
count_bits(a));
System.out.printf("Total bits in %d: %d\n", b,
count_bits(b));
}
}
// this code is contributed by phasing17
# function to count the number of bits in a number n
def count_bits(n):
# bin(n) returns a binary string representation of n preceded by '0b' in python
binary = bin(n)
# we did -2 from length of binary string to ignore '0b'
return len(binary)-2
a = 65
b = 183
print(f"Total bits in {a}: {count_bits(a)}")
print(f"Total bits in {b}: {count_bits(b)}")
# This code is contributed by udit
// C# code to implement the approach
using System;
class GFG {
// function to count the number of bits in a number n
static int count_bits(int n)
{
// return the length of the binary string
return Convert.ToString(n, 2).Length;
}
// Driver Code
public static void Main(string[] args)
{
int a = 65;
int b = 183;
// function call
Console.WriteLine("Total bits in " + a + " : "
+ count_bits(a));
Console.WriteLine("Total bits in " + b + " : "
+ count_bits(b));
}
}
// this code is contributed by phasing17
// JavaScript program to implement the approach
// function to count the number of bits in a number n
function count_bits(n)
{
// toString(2) returns the binary string
// representation of the number n
let binary = n.toString(2);
// returning the length of the binary string
return binary.length;
}
let a = 65;
let b = 183;
console.log("Total bits in", a, ":", count_bits(a));
console.log("Total bits in", b, ":", count_bits(b));
// This code is contributed by phasing17
OutputTotal bits : 7
Total bits : 8
Time Complexity : O(logn)
Auxiliary Space : O(1)
Similar Reads
Python Bin | Count total bits in a number Given a positive number n, count total bit in it. Examples: Input : 13 Output : 4 Binary representation of 13 is 1101 Input : 183 Output : 8 Input : 4096 Output : 13 We have existing solution for this problem please refer Count total bits in a number link. Approach#1: We can solve this problem quick
3 min read
Count unset bits of a number Given a number n, count unset bits after MSB (Most Significant Bit).Examples : Input : 17 Output : 3 Binary of 17 is 10001 so unset bit is 3 Input : 7 Output : 0 A Simple Solution is to traverse through all bits and count unset bits. C++ // C++ program to count unset bits in an integer #include <
7 min read
Count total set bits in an array Given an array arr, the task is to count the total number of set bits in all numbers of that array arr. Example: Input: arr[] = {1, 2, 5, 7}Output: 7Explanation: Number of set bits in {1, 2, 5, 7} are {1, 1, 2, 3} respectively Input: arr[] = {0, 4, 9, 8}Output: 4 Approach: Follow the below steps to
5 min read
Count set bits in an integer Write an efficient program to count the number of 1s in the binary representation of an integer.Examples : Input : n = 6Output : 2Binary representation of 6 is 110 and has 2 set bitsInput : n = 13Output : 3Binary representation of 13 is 1101 and has 3 set bits[Naive Approach] - One by One CountingTh
15+ min read
Count set bits in a range Given a non-negative number n and two values l and r. The problem is to count the number of set bits in the range l to r in the binary representation of n, i.e, to count set bits from the rightmost lth bit to the rightmost rth bit. Constraint: 1 <= l <= r <= number of bits in the binary rep
6 min read