See inside the black box, the value of la here is 0. In the sentence you marked, la == 0 ? 1 : la - 1, the output value is indeed 1 (because la == 0 established), but there is no place in this line to assign a value to la, so the value of la will not change and is still 0.
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See inside the black box, the value of
lahere is 0. In the sentence you marked,la == 0 ? 1 : la - 1, the output value is indeed 1 (becausela == 0established), but there is no place in this line to assign a value tola, so the value oflawill not change and is still 0.la==0?1:la-1
This statement does nothing at all and needs to be changed to;
la=la==0?1:la-1