Write the definition of a class clock. the class has no constructors and three instance variables. one is of type int called hours, initialized to 12, another is of type boolean called isticking, and the last one is of type integer called diff. instructor notes: recall that you can initialize an instance variable on the same line that you declare it.

Use a physical stopwatch to record the length of time it takes to run the program. calculate the difference obtained by calls to the method system.currenttimemillis() just before the start of the algorithm and just after the end of the algorithm. calculate the difference obtained by calls to the method system.currenttimemillis() at the start of the program and at the end of the program so that the elapsed time includes the display of the result. use the value returned by the method system.currenttimemillis() just after the end of the algorithm as the elapsed time.