please show work

What is the worst-case complexity of the following code?

double reduce (double *a, double *b, int n) { double s = 0; for (int i = 0, i < n, i++) { b[i] = a[i] * a[i]; for (int j = 0; j < n; j++) { s += a[j] + b[j]; } } return s; }