public int findLast (int[] x, int y) {
//Effects: If x==null throw
NullPointerException
// else return the index of the last element
// in x that equals y.
// If no such element exists, return -1
for (int i=x.length-1; i > 0; i--)
{
if (x[i] == y)
{
return i;
}
}
return -1;
}
// test: x=[2, 3, 5]; y = 2
// Expected = 0
- Fault：for循环中应为i>=0
- Not execute：x=null ; y=3
- Not result in an error state: x=[3,3,3]; y=3
- Results in an error, but not a failure：x=[0,0,0]; y=3
public static int lastZero (int[] x) {
//Effects: if x==null throw
NullPointerException
// else return the index of the LAST 0 in x.
// Return -1 if 0 does not occur in x
for (int i = 0; i < x.length; i++)
{
if (x[i] == 0)
{
return i;
}
} return -1;
}
// test: x=[0, 1, 0]
// Expected = 2
- Fault: for循环应为for(int i=x.length-1;i>=0;i--)
- Not execute：x=null ; y=3
- Not result in an error state: x=[3]
- Results in an error, but not a failure：x=[1,1,0]