Category Archives: Bit Magic

Count set bits in an integer

Write an efficient program to count number of 1s in binary representation of an integer. Examples Input : n = 6 Output : 2 Binary representation of 6 is 110 and has 2 set bits Input : n = 13 Output : 3 Binary representation of 11 is 1101 and has 3 set bits 1.… Read More »

Little and Big Endian Mystery

What are these? Little and big endian are two ways of storing multibyte data-types ( int, float, etc). In little endian machines, last byte of binary representation of the multibyte data-type is stored first. On the other hand, in big endian machines, first byte of binary representation of the multibyte data-type is stored first.

Check for Integer Overflow

Write a “C” function, int addOvf(int* result, int a, int b) If there is no overflow, the function places the resultant = sum a+b in “result” and returns 0. Otherwise it returns -1. The solution of casting to long and adding to find detecting the overflow is not allowed.

Position of rightmost set bit

Write a one line C function to return position of first 1 from right to left, in binary representation of an Integer. I/P 18, Binary Representation 010010 O/P 2 I/P 19, Binary Representation 010011 O/P 1