Suppose that David needs to test a function (named, compdate) that compares dates with the following specification:

int compdate(int year1, int month1, int day1, int year2, int month2, int day2);

/* compdate returns 0 if date1 = date2, -1 if date1 before date2, 1 if date1 after date2, -2 if any element of any date is invalid; valid years are all integers (<0 >

David decides to use a random testing scheme to test the compdate function, he also decides to run 200 tests where each test is performed by the following function:

int randomtest_compdate() {

int i;

for (i=0; i<200; i++){ int y1 = random_int(); /* returns a random 32 bit value */ int y2 = random_int(); int m1 = (random_int() % 11) + 1; int m2 = (random_int() % 11) + 1; int d1 = (random_int() % 30) + 1; int d2 = (random_int() % 30) + 1; int c = compdate(y1,m1,d1,y2,m2,d2); oracle(y1,m1,d1,y2,m2,d2,c);

}

}

Assuming that oracle function does a good job of checking compdates correctness:

Discuss the random testing approach and propose how to improve it.

For each improvement, explain the weakness of the original scheme.