Consider an array 'A' of 1st n natural numbers randomly permuted. Consider an array B formed from array A as given below

B(k) = number of elements from A(1) to A(k-1) which are smaller than A(k)

Obviously B(1) = 0;

i) Given A can you find B in O(n)

ii) Given B can you find A in O(n)

Disclaimer: The question was asked to me during GSachs interview and of course I was unable to answer. I am still unable to figure out the solution

B(k) = number of elements from A(1) to A(k-1) which are smaller than A(k)

Obviously B(1) = 0;

i) Given A can you find B in O(n)

ii) Given B can you find A in O(n)

Disclaimer: The question was asked to me during GSachs interview and of course I was unable to answer. I am still unable to figure out the solution