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#Anyone know what is causing this error? I have tried so many different things
lusty spearBOT
celest tartan
void createNoList(vector<PCBNoList>& pcb, int p) {
PCBNoList child;
child.parent = p;
if (pcb[p].firstChild == -1) {
pcb[p].firstChild = pcb.size();
}
else {
int youngest_sibling = pcb[p].firstChild;
while (pcb[youngest_sibling].younger != -1) {
youngest_sibling = pcb[youngest_sibling].younger;
}
pcb[youngest_sibling].younger = pcb.size();
child.older = youngest_sibling;
}
pcb.push_back(child);
}
sand lodge
You are accessing an element out of range of the vector, the message says very clearly.
Debug to see the offending code and values.
celest tartan
Debug to see the offending code and values.
I put breakpoints throughout and line 31 is the culprit
sand lodge
Look at the values.
celest tartan
how would while (pcb[youngest_sibling].younger != -1) trip an out of bounds error, when its just not equivalent to
sand lodge
The index can be too big.
celest tartan
struct PCBNoList {
int parent;
int firstChild;
int younger;
int older;
};
might have to do with firstChild being unitialized
nvm
bc that code actually initializes it
struct PCBNoList {
int parent;
int firstChild;
int younger;
int older;
};
thats the whole program if anyone can take a crack at it I would be very grateful I'm stumped
acoustic oxide
In line 81 you call createNoList with argument pcbV2 which is an empty vector. Then in line 31 you do if (pcb[p].firstChild == -1), but pcb[p] does not exist, because pcb is empty.
And thus it crashes.
celest tartan
In line 81 you call `createNoList` with argument `pcbV2` which is an empty vecto...
Ah I see, so should I implement a check to see if there is no parent, and then what should be done if there is none?
acoustic oxide
I don't know, that's for you to decide. You could do pcb.push_back(p); to add p to the vector. If that makes sense for what you're trying to do is another question. I didn't look closely enough to figure out the goal.
celest tartan
I don't know, that's for you to decide. You could do `pcb.push_back(p);` to add ...
Well it's for an operating systems course, and it's supposed to simulate the creation and destruction of process control blocks with and without linked lists, this is without linked lists, where each has a parent and children, I did what I thought was logically correct in the second create function but now I just need to figure out what to do when there is no parent, maybe create another create method for initializing?
fixed it
void createNoList(vector<PCBNoList>& pcb, int p) {
PCBNoList child;
if (pcb.size() <= 0)
{
child.parent = -1;
child.firstChild = -1;
child.younger = -1;
child.older = -1;
pcb.push_back(child);
}
child.parent = p;
if (pcb.at(p).older == -1) {
pcb[p].firstChild = pcb.size();
}
else {
int youngest_sibling = pcb[p].firstChild;
while (pcb[youngest_sibling].younger != -1) {
youngest_sibling = pcb[youngest_sibling].younger;
}
pcb[youngest_sibling].younger = pcb.size();
child.older = youngest_sibling;
}
pcb.push_back(child);
}
Thank you for the help
!solved
lusty spearBOT