Question

Here is my code where the problem happens, I’ve bolded line 90 (where the error message says the problem is originating) [edit: I can’t figure out how to bold inside a code block, I marked it with an arrow instead]:

while ((l<=list_L.size())&&(i<=list_I.size())) {
    if (list_I.get(i).url.compareTo(list_L.get(l).src) == 0) {   //<--- LINE 90
        int firstmatch = l;
        int outgoing = 1;
        l++;

        while (list_I.get(i).url.compareTo(list_L.get(l).src) == 0) {
            outgoing++;
            l++;
        }

        l = firstmatch;
        for (int k=0; k<outgoing; k++) {
            list_R.add(new Triplet(list_L.get(l).src, list_L.get(l).dest, list_I.get(i).rank / outgoing));
            l++;
        }
    }
    else {
        sum_T += list_I.get(i).rank; //This shouldn't happen in this case...
    }

    i++;
}

And here is the error message:

Exception in thread “main” java.lang.IndexOutOfBoundsException: Index:
118981, Size: 118981
at java.util.ArrayList.RangeCheck(Unknown
Source)
at java.util.ArrayList.get(Unknown Source)
at
PageRank.main(PageRank.java:90)

I don’t know what is going wrong since it isn’t a nullpointer exception like I would expect if something WAS wrong…

UPDATE:
Ok I fixed the problem in the initial location but now it’s happening here:

for (int p=0; p<list_I2.size(); p++) {
    L2_norm += Math.pow((list_I.get(p).rank - list_I2.get(p).rank), 2); // <-- LINE 146
}

Error Message:

Exception in thread “main” java.lang.IndexOutOfBoundsException: Index:
118981, Size: 118981
at java.util.ArrayList.RangeCheck(Unknown
Source)
at java.util.ArrayList.get(Unknown Source)
at
PageRank.main(PageRank.java:146)

list_I and list_I2 are the same size and I have confirmed so in debugging.

Answer 1

the condition should be :

while ((l<list_L.size())&&(i<list_I.size()))

not

while ((l<=list_L.size())&&(i<=list_I.size()))

If a list has a size of X, the last index of the list is X-1.