# Case ![](https://i.imgur.com/Pb9oxbO.png) # Coding ![](https://i.imgur.com/3S8XAhg.png) ```python def checkpin(pin): //check 0 ist falsche Eingabe //check 1 ist richtige check1 = 0 check2 = 0 for i in range(1,3): if(pin[0]!=pin[i]): check1 = 1 break for i in range(1,3): if(pin[i-1] != (pin[i]-1)): check2 = 1 break if((check1 + check2) == 2) return 1 else return 0 arr = [0, 0, 0, 0] => 0 arr = [1, 2, 3, 4] => 0 arr = [1, 2, 0, 0] => 1 checkpin(arr) ```