Given two numbers ‘a’ and b’. Write a program to count number of bits needed to be flipped to convert ‘a’ to ‘b’.
Input : a = 10, b = 20 Output : 4 Binary representation of a is 00001010 Binary representation of b is 00010100 We need to flip highlighted four bits in a to make it b. Input : a = 7, b = 10 Output : 3 Binary representation of a is 00000111 Binary representation of b is 00001010 We need to flip highlighted three bits in a to make it b.
1. Calculate XOR of A and B. a_xor_b = A ^ B 2. Count the set bits in the above calculated XOR result. countSetBits(a_xor_b)
XOR of two number will have set bits only at those places where A differs from B.
Thanks to Sahil Rajput for providing above implementation.
To get the set bit count please see this post: Count set bits in an integer
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
- Check if bits of a number has count of consecutive set bits in increasing order
- Count pairs (A, B) such that A has X and B has Y number of set bits and A+B = C
- Count unset bits of a number
- Count total bits in a number
- Program to count number of set bits in an (big) array
- Count number of bits changed after adding 1 to given N
- Toggle bits of a number except first and last bits
- Count set bits in a range
- Count set bits in an integer
- Count unset bits in a range
- Range query for count of set bits
- Python | Count set bits in a range
- Count total set bits in all numbers from 1 to n
- Python | Count unset bits in a range
- Count set bits in an integer using Lookup Table
Improved By : Mithun Kumar