following code(even as sum of two primes) gives a segmentatioon error.plz help me to sort out that

vector v(2); int isprime(int n) {

for(int i=2;i<=sqrt(n);i++)
{   

    if(n%i==0)
    return 0;
}
 if(n==1)
 return 0;
 else
return 1;

}

vector Solution::primesum(int n)

{ for(int i=3;i

{
    if(isprime(i)==1 && isprime(n-i)==1)
    {
        v.push_back(i);
        v.push_back(n-i);
        return v;
    }

}

}