I don't understand the setup. Is there a precise statement about what this "indication" from -3 to 3 means? You say that, if the feedback is 0 then your guess is within a range of 100 (presumably meaning that your guess is at most 49 units away from the true value). What would a value of +1 mean? That you're 50 units away? What would you get for feedback if you're 200 units away? Would that just register as a +3 or something?
Also, does this mean that x could be 1 and therefore if you guess 0 (even though 0 is not a possible value of x) the feedback would be 0?