Chapter 2, Problem 19P

Develop a well-structured function to determine the elapsed days in a year. The function should be passed three values: $\text{mo = the month }\left(1-12\right),\text{ da = the day }\left(1-31\right)\text{ and leap = }$ (0 for non-leap year and 1 for leap year). Test it for January 1, 1999; February 29, 2000; March 1, 2001; June 21, 2002; and December 31, 2004. Hint: a nice way to do this combines the for and the switch structures.