软件测试：2.Two Faulty Programs
Questions:
1.Identify the fault;
2.If possible, identify a test case that does not execute the fault; (Reachability)
3.If possible, identify a test case that executes the fault, but does not result in an error state;
4.If possible, identify a test case that result in an error, but not a failure.
Answers:
1.左侧函数fault位于第7行的for循环里的循环条件，循环结束的判断条件有误，对应代码应为
for(int i=x.length-1; i>=0; i--)
右侧函数fault位于第7行的for循环里的循环条件，循环遍历数组的方向有误，找到最后一个0的函数，数组应该从后往前遍历，对应代码应为
for(int i=x.length-1; i>=0; i--)
2.Identify a test case that does not execute the fault.
左侧函数：
test: x=[]; y=3
右侧函数：
test: x=[]
3.Identify a test case that executes the fault, but does not result in an error state.
左侧函数：
test: x=[2,3,5]; y=3
右侧函数：
test: x=[0]
4.Identify a test case that result in an error, but not a failure.
左侧函数：
test: x=[2,3,5]; y=1
右侧函数：
test: x=[1,0,1]
如果不足，欢迎指教，感激不尽