Getting SIGABRT in c++ in the following program

Question

I submitted this problem in spoj and this is showing runtime error(SIGABRT). It's working properly on my machine and on Ideone.com but showing error there. any reason? I am writing my code here: what I am trying to do is to calculate primes of order 10^8 and handling some operations on it. here is the problem link: http://www.spoj.com/problems/CPRIME

#include<iostream>
#include<vector>
#include<cmath>
#include<cstdio>

using namespace std;
int n=100000001;
int d = 10001;//3163;
vector<int>num(100000001,0);

int main (){
    //atkin's seive for generating prime numbers of order 10^8
for (int x = 1; x <= d; x++){
        for (int y = 1; y <= d; y++){
            long long sqx=x*x,sqy=y*y;
            long long m =(3*sqx)-sqy;
             //m=m-sqx;
             if(m<n){
                 if(x>y&&m%12==11)num[m]=num[m]^1;
                 m=m+2*sqy;
                 if(m<n){
                    if(m%12==7)num[m]=num[m]^1;
                    m=m+sqx;
                    if(m<n&&(m%12==1||m%12==5))num[m]=num[m]^1;
                    }
                 }

            }
    }
   for (int i=5;i<d;i++){
       if(num[i]){
           for(int j=i*i;j<n;j+=i*i)num[j]=0;
       }
   }   //sieve finished here
    //main code start from here and for loop is for counting number of primes
    //less than or equal to that number.
    int add=2;
    num[2]=1;num[3]=2;
  for(int a=4;a<n;a++){
      if(num[a]){
          //if(a==2||a==3||a==5)cout<<num[a]<<" "<<a<<" ";
          add++;
          num[a]=add;
      }
      else num[a]=add;
  }
  //cout<<num[2]<<" "<<num[3]<<endl;
  while(1){
      int t;
      scanf("%d",&t);
      if(t==0)break;
      double ans=(num[t]-t*1.0/(log(t)))*100.0/num[t];
      if(ans<0)ans*=-1.0;
      printf("%.1lf\n",ans);
  }
  return 0;


}

Answer 1

You should allocate num as a array from heap instead of stack int* num=new int[size]; this will work fine.

Answer 2

100000001*4 = 400000004 bytes
              400000.004 kilo bytes
              400.000004 mega bytes

You need half a gig minimum! Since the vector adds some overhead too.

The OS will go bannanas trying to fit that into the heap.

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As a sidenote: calculating primes with O(n^2) time is the most naive and slow approach. Consider using Atkins Sieve.

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Make sure you're not dividing by zero. 100.0/num[t]. Usually division by zero generates SIGFPE but hardware can also generate SIGABRT on such division.