Question

Bit Manipulation
I having problem understand how bit manipulation in C++ works.

Problem question: http://www.spoj.com/problems/FRND/

Solution:
http://spoj-solutions.blogspot.my/2014/05/frnd-friendship.html

I don't know how the following codes works:
1) Why they need bit size 20 to hold array ?
2) (temp>>i) & 1
3) bit[i] * (n-bit[i])* (1< 10 years ago

Answer 1

http://www.learncpp.com/cpp-tutorial/38-bitwise-operators/ and http://www.bogotobogo.com/cplusplus/quiz_bit_manipulation.php
might help