4. (7 points) Divide and Conquer You are trying to calculate 221 a) (1 point) How many multiplications are needed to compute 221 using a simple brute force algorithm? b) (3 points) Show the steps of how to calculate 221 using a divide and conquer algorithm. (1 point) How many multiplications were used by the divide and conquer algo- rithm. c) d) (2 points) Compare the asymptotic number of multiplications used by the brute force algorithm and the divide and conquer algorithm