dynamic array? or varrying the size of the array based on something?

i think i fixed it; i removed the = sign in my for loop

 average0 = 0;
  sum0= 0;
  for (i0 = 0; i0 <= (SnumRead); i0++)
  {
    sum0 = sum0 + pulse0[i0];
  }
  average0 = sum0 / SnumRead;
  rate0 =  (float)1000000 / average0;