使用PICT进行测试，但测试用例不完整

Question

我正在PICT中测试三角形问题。我正在测试一个三角形是等边三角形，等腰三角形还是斜角三角形。问题是我从来没有得到等边三角形。

Side1:  5,6,7,8,9,10 
Side2:  5,6,7,8,9,10 
Side3:  5,6,7,8,9,10 
Type:   equilateral, isosceles, scalene 

IF (([Side1] = [Side2]) OR ([Side2] = [Side3]) OR ([Side3] = [Side1])) THEN [Type] = "isosceles" ELSE [Type] = "scalene"; 
IF (([Side1] = [Side2]) AND ([Side2] = [Side3]) AND ([Side3] = [Side1])) THEN [Type] = "equilateral"; 

但随意的事情是，当我改变的最后一行到

IF (([Side1] = [Side2]) AND ([Side2] = [Side3]) AND ([Side3] = [Side1])) THEN [Type] = "isosceles"; 

我随机得到这会导致一个等边三角形的值。我如何确保在正确的代码中也有这些值？

Answer 1

试试这个：

Side1:  5,6,7,8,9,10 
Side2:  5,6,7,8,9,10 
Side3:  5,6,7,8,9,10 
Type:   equilateral, isosceles, scalene 

IF (([Side1] = [Side2] AND [Side2] <> [Side3]) OR ([Side2] = [Side3] AND [Side3] <> [Side1]) OR ([Side3] = [Side1] AND [Side1] <> [Side2])) THEN [Type] = "isosceles"; 
IF (([Side1] = [Side2]) AND ([Side2] = [Side3])) THEN [Type] = "equilateral"; 
IF ([Side1] <> [Side2] AND [Side2] <> [Side3] and [Side3] <> [Side1]) THEN [Type] = "scalene"; 

的原因是，你的逻辑案件之间的重叠，你要明确你的条件，比如有针对每一种情况下只有一个结果。上面的例子工作;我验证了它。祝你好运！

Answer 2

您必须使用无条件限制（不变量）这是在PICT中可用。

在这种情况下，必须替换该行

IF (([Side1] = [Side2]) AND ([Side2] = [Side3]) AND ([Side3] = [Side1])) THEN [Type] = "equilateral"; 

与这一个：

[Side1] = [Side2] and [Side2] = [Side3] and [Side3] = [Side1]; 

因此生成的测试集将包含至少1等边三角形。

参考文档细节：http://www.amibugshare.com/pict/help.html