Modify your program by introducing Pthreads mutex variables, so that accesses to the shared variable are properly synchronized. Try your synchronized version with the command line parameter set to 1, 2, 3, 4, and 5. Accesses to the shared variables are properly synchronized if (i) each iteration of the loop in SimpleThread() increments the variable by exactly one and (ii) each thread sees the same final value. It is necessary to use a Pthreads barrier [2] in order to allow all threads to wait for the last to exit the loop.

Consider the following statements: struct nametype{string first; string last; }; struct coursetype{string name; int callnum; int credits; char grade; }; struct studenttype{nametype name; double gpa; coursetype course; }; studenttype student; studenttype classlist[100]; coursetype course; nametype name; mark the following statements as valid or invalid. if a statement is invalid, explain why. a.) student. course. callnum = "csc230"; b.) cin > > student. name; c.) classlist[0] = name; d.) classlist[1].gpa = 3.45; e.) name = classlist[15].name; f.) student. name = name; g.) cout < < classlist[10] < < endl; h.) for (int j = 0; j < 100; j++)classlist[j].name = name; i.) classlist. course. credits = 3; j.) course = studenttype. course;