c++ - Large vector "Segmentation fault" error -

i have gathered large amount of extremely useful information other peoples' questions , answers on so, , have searched duly answer 1 well. unfortunately have not found solution problem.

the following function generate list of primes:

void genprimes (std::vector<int>* primesptr, int upperbound = 10) {   std::ofstream log;   log.open("log.txt");    std::vector<int>& primesref = *primesptr;    // populate primes non-neg reals   (int = 2; <= upperbound; i++)     primesref.push_back(i);   log << "generated reals successfully." << std::endl;   log << primesref.size() << std::endl;    // eratosthenes sieve remove non-primes   (int = 0; < primesref.size(); i++) {     if (primesref[i] == 0) continue;     int jumpstart = primesref[i];     (int jump = jumpstart; jump < primesref.size(); jump += jumpstart) {       if (primesref[i+jump] == 0) continue;       primesref[i+jump] = 0;     }   }   log << "executed eratosthenes sieve successfully.\n";    (int = 0; < primesref.size(); i++) {     if (primesref[i] == 0) {       primesref.erase(primesref.begin() + i);       i--;     }   }   log << "cleaned list.\n";   log.close(); } 

is called by:

  const int size = 500;   std::vector<int>* primes = new std::vector<int>[size];   genprimes(primes, size); 

this code works well. however, when change value of size larger number (say, 500000), compiler returns "segmentation error." i'm not familiar enough vectors understand problem. appreciated.

you accessing primesref[i + jump] i primesref.size() - 1 , jump primesref.size() - 1, leading out of bounds access.

it happening 500 limit, happen not have bad side effects out of bound access @ moment.

also note using vector here bad choice every erase have move of following entries in memory.