1. The findLast() function
Fault: In the for loop, it should search to 0, not 1;
Test1: no test case will not execute the fault
Test2: no test case will not result in an error state, cause array start with 0;
Test3: x=[2,3,4]; y=3, the case results in an error that can not search to 0, but it does not cause a failure;
2. The lastZero() function
Fault:In the for loop, it start searching with 0, while the function aims to find the last 0, so it should start with the last one in the x;
Test1: x=[1,2,3], the case does not execute the fault, because it does not have 0;
Test2: x=[0], the case execute the fault, but it does not result in an error state;
Test3: x=[1,0,1], the case result in an error, but it does not cause a failure;