1. (15%) Consider a computer system with three users: Alice, Bob, and Cyndy. Alice owns the file a, and Bob and Cyndy can read it. Bob owns the file b, and Cyndy can read and write the file b, but Alice can only read it. Cyndy owns the file c, but neither Alice and Bob can read or write it. If a user owns a file, he/she can also execute the file.(a) Create the ACM (access control matrix) of the system.(b) Show the ACL of the ACM and the CL of the ACM.(c) Cyndy gives Alice permission to read c, and Alice removes Bob's ability to read a. Show the ACM after these changes.

Write a program that performs a simple n-body simulation, called "jumping leprechauns." this simulation involves n leprechauns, numberd 1 to n. it maintains a gold value g_i for each leprechaun i, which begins with each leprechaun starting out with a million dollars worth of gold, that is, g_i = 1000000 for each i = 1,. in addition, the simulation also maintains, for each leprachaun, i, a place on the horizon, which is represented as a double-precision floating point number, x_i. in each iteration of the simulation, the simulation processes the leprachauns in order. processing a leprachaun i during its iteration begins by computing a new place on the horizon for i, which is determined by the assignment: