Exercise 1.6 The following for-next loop statements computes a function f(n), please analyze and give (1) the precise f(n) with n being the input and (2) the big-O notation for each expression, i.e., g(n). The initial value of x is 0. 3. for i = 1 to n; for j = i to n; for k = 1 to j; x := x + 1;