黑盒测试：等价类划分法（弱健壮）

问题

构造下述三角形问题的弱健壮的等价类测试用例。

• 三角形问题：输入三个不超过100的正整数作为三角形的三条边，判断三角形是等边三角形、等腰不等边三角形、完全不等边三角形还是不能构成三角形。

解答

有效等价类划分：

• R1 = {<a, b, c>: the triangle with sides a, b, and c is equilateral}
• R2 = {<a, b, c>: the triangle with sides a, b, and c is isosceles}
• R3 = {<a, b, c>: the triangle with sides a, b, and c is scalene}
• R4 = {<a, b, c>: sides a, b, and c do not form a triangle}

Test Case	a	b	c	Expected Output
WR1	5	5	5	Equilateral
WR2	2	2	3	Isosceles
WR3	3	4	5	Scalene
WR4	4	1	2	Not a triangle
WR5	-1	5	5	Value of a is out of range
WR6	5	-1	5	Value of b is out of range
WR7	5	5	-1	Value of c is out of range
WR8	101	5	5	Value of a is out of range
WR9	5	101	5	Value of b is out of range
WR10	5	5	101	Value of c is out of range
WR11	5.1	5	5	Value of a is not a integer
WR12	5	5.1	5	Value of b is not a integer
WR13	5	5	5.1	Value of c is not a integer