Write a function string cipher(string s, int n) which takes a c++ string and encrypts it by shifting each character value by the number n, for example "abcd" shifted by 2 becomes "cdef". test your method by encrypting a string (shift by n) and then decrypting it (shift by-n).

Let r be a robotic arm with a fixed base and seven links. the last joint of r is a prismatic joint, the other ones are revolute joints. give a set of parameters that determines a placement of r. what is the dimension of the configuration space resulting from your choice of parameters?