Given an integer 
. The task is to find the number of bits changed after adding 1 to the given number.
Examples:
Input : N = 5 Output : 2 After adding 1 to 5 it becomes 6. Binary representation of 5 is 101. Binary representation of 6 is 110. So, no. of bits changed is 2. Input : N = 1 Output : 2
There are three approaches to find the number of changed bits in the result obtained after adding 1 to the given value N:
- Approach 1: Add 1 to given integer and compare the bits of N and the result obtained after addition and count the number of unmatched bit.
- Approach 2: In case if 1 is added to N, then the total number of bits changed is defined by the position of 1st Zero from right i.e. LSB as zero. In this case, 1 is added to 1 then it got changed and passes a carry 1 to its next bit but if 1 is added to 0 only 0 changes to 1 and no further carry is passed.
- Approach 3: For finding a number of changed bits when 1 is added to a given number take XOR of n and n+1 and calculate the number of set bits in the resultant XOR value.
Below is the implementation of the Approach 3:
C++
// CPP program to find the number// of changed bit#include <bits/stdc++.h>using namespace std;// Function to find number of changed bitint findChangedBit(int n){ // Calculate xor of n and n+1 int XOR = n ^ (n + 1); // Count set bits in xor value int result = __builtin_popcount(XOR); // Return the result return result;}// Driver functionint main(){ int n = 6; cout << findChangedBit(n) << endl; n = 7; cout << findChangedBit(n); return 0;} |
Java
// Java program to find the number// of changed bitclass GFG {// Function to find number of changed bitstatic int findChangedBit(int n){ // Calculate xor of n and n+1 int XOR = n ^ (n + 1); // Count set bits in xor value int result = Integer.bitCount(XOR); // Return the result return result;}// Driver codepublic static void main(String[] args) { int n = 6; System.out.println(findChangedBit(n)); n = 7; System.out.println(findChangedBit(n));}}// This code contributed by Rajput-Ji |
Python3
# Python 3 program to find the number# of changed bit# Function to find number of changed bitdef findChangedBit(n): # Calculate xor of n and n+1 XOR = n ^ (n + 1) # Count set bits in xor value result = bin(XOR).count("1") # Return the result return result# Driver Codeif __name__ == '__main__': n = 6 print(findChangedBit(n)) n = 7 print(findChangedBit(n))# This code is contributed by# Surendra_Gangwar |
C#
// C# program to find the number// of changed bitusing System; class GFG {// Function to find number of changed bitstatic int findChangedBit(int n){ // Calculate xor of n and n+1 int XOR = n ^ (n + 1); // Count set bits in xor value int result = bitCount(XOR); // Return the result return result;}static int bitCount(int x){ // To store the count // of set bits int setBits = 0; while (x != 0) { x = x & (x - 1); setBits++; } return setBits;}// Driver codepublic static void Main(String[] args) { int n = 6; Console.WriteLine(findChangedBit(n)); n = 7; Console.WriteLine(findChangedBit(n));}}/* This code contributed by PrinciRaj1992 */ |
Javascript
<script>// Javascript program to find the number// of changed bit// Function to find number of changed bitfunction findChangedBit(n){ // Calculate xor of n and n+1 let XOR = n ^ (n + 1); // Count set bits in xor value let result = bitCount(XOR); // Return the result return result;}function bitCount(x){ // To store the count // of set bits let setBits = 0; while (x != 0) { x = x & (x - 1); setBits++; } return setBits;}// Driver function let n = 6; document.write(findChangedBit(n) + "<br>"); n = 7; document.write(findChangedBit(n));</script> |
Output:
1 4
Feeling lost in the world of random DSA topics, wasting time without progress? It’s time for a change! Join our DSA course, where we’ll guide you on an exciting journey to master DSA efficiently and on schedule.
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!
… [Trackback]
[…] Information on that Topic: geeksforgeeks.org/count-number-of-bits-changed-after-adding-1-to-given-n/ […]