A function foo takes three integers as input arguments, i.e., foo(int a, int b, int c). The three inputs represent the three sides of a triangle in centimeter. The function is expected to return the type of a triangle: equilateral, isosceles, or scalene. Assume the domains of the three variables are 1 a 100, 50 b 150 and 100 c 200, respectively. A test case is in a tuple format <a, b, c, expected_output> with test inputs and the expected output.

S1 is a set of test cases for the Boundary Value Analysis approach. (0.5 pt)

S1 =

S2 is a set of test cases for the Robustness testing approach. (0.5 pt)

S2 S1 =

S3 is a set of tests cases for the Robust Worst-Case testing approach. Are there any types of triangles that S3 cannot reveal? If yes, what are they? If no, why? (1 pt)