int main(){
int A[10], i, count = 0,sum=0;
for (i = 0; i < 10; i++)
{
cout << "A[" << i << "]=";
cin >> A[i];
}
for (i = 2; i<= A[i]/2; ++i)
{
if (A[i] % i == 0)
{
count = 1;
break;
}
if (count == 0){
sum = sum + A[i];
}
}
cout << "sum =" << sum << endl;
}
Lines 4-8: A[] is uninitialized. i.e. contains garbage.
line 9: You're trying to use A[i] as part of the termination condition of the loop, but you've never initialized A[i]. Since you don't know how large i will get to find the first 10 primes, you really want the termination condition to be count < 10.
Line 11: Again, you're trying to use an uninitialized array location.
Line 14: You're breaking out of the for loop on the first non-prime number.
Lines 13,16: You're using count as a flag to indicate if a number is prime or not. It would be better to used count as the number of prime numbers you've inserted in the array.
Line 17: Again, you trying to add an uninitialized array location.
What you're missing here is that when you find a prime number, you want to add it to the array and to the sum.