complexity of code

[tarun91]

what's the time complexity of following code and why?

for (i = 2; i*i <= n; i++) {
  if (a[i]) {
    for (j = i*i; j <= n; j+=i) {
      a[j] = 0;
    }
  }  
}

one more question, is structure a primitive data type, if so, why?

[kbw]

The algorithm's a trick question.

[binarybob350]

is structure a primitive data type, if so, why?

Not in my opinion. int, char, long, float, double... are primitive data types. struct and class are used to make custom/complex data types.