Another program crash on vector.push_back() - c++

Question

I am writing a program that reads in data from text files, sorts the data in various ways and then uses the sorted data for other calculations. Let me say that in int main(){ } there is one large for-loop that contains many other for-loops and that the segment of code that I am posting is just one of those many for-loops inside the main one.
for(t=(compare.t - 1000)*2 - 12 ;t< ( (compare.t - 1000)*2 + 12 /);t++){
rank.push_back(vector <int>() );p++;
for(ii=111;ii<2489;ii++){
if(M_screened[a][ii].size()>0){
if( fabs(M_screened[a][ii][0].t-(t*0.5 + 1000.0)) <0.257 ){
cout<<"ii = "<<ii<<" t = "<<t<<" sizeof(rank) = "<<rank.size()<<" p = "<<p;
cout<<" rank["<<p<<"].size() = "<<rank[p].size()<<endl;
cout<<" "<<endl;
cout<<"address = "<<&rank[p][rank[p].size()-1];
rank[p].push_back(ii);
cout<<" "<<endl;
}
}
}
foutT<<t*0.5 + 1000<<" "<<frequency[a][t]<<endl;} //end t-loop
All of the cout statements were just part of my own error checking process. Also, the large for-loop that contains the above code segment is able to run 2 iterations prior to crashing on the third (every single time).
Basically what I've narrowed it down to is crashing on the push_back() function. Parameter values at the time of crash:
t=177, p = 10, ii = 873, sizeof(rank) = 11, rank[10].size() = 1
Here is the error message I get from Microsoft Visual Studio :
Unhandled exception at 0x0000000077993290 (ntdll.dll) in Muon_fitting7_7_2014_statistics.exe: 0xC0000005: Access violation reading location 0x0000038085FFA1E8.
If I can provide any additional information please let me know.

Answer 1

I am assuming you've initialized P to zero or some such thing when declared and that is actually your problem.
for(t=(compare.t - 1000)*2 - 12 ;t< ( (compare.t - 1000)*2 + 12 /);t++)
{
rank.push_back(vector <int>() );p++;
for(ii=111;ii<2489;ii++)
{
if(M_screened[a][ii].size()>0){
if( fabs(M_screened[a][ii][0].t-(t*0.5 + 1000.0)) <0.257 ){
rank[p].push_back(ii);
}
}
}
}
At first, rank has no elements, then you push back and increment p. Now rank as 1 element but you need to use rank[p-1] to access it as p is already 1. That or initialize p to -1 to start so when you increment it, its at zero. Vector [] access is zero based.
So, try this :
int p = -1;
for(t = ((compare.t - 1000)*2 - 12);t < ((compare.t - 1000)*2 + 12);++t)
{
rank.push_back(vector <int>() );
++p;
for(ii=111;ii<2489;++ii)
{
if (M_screened[a][ii].size() > 0)
{
if (fabs(M_screened[a][ii][0].t-(t*0.5 + 1000.0)) < 0.257)
{
rank[p].push_back(ii);
}
}
}
}