>>38
"this sums up to [(n/2)*(-1) + n] = -n/2 + 2n/2 = n/2"
it does not and this is not correct, in fact it is (-1)*(n-1)*(1/2) + n; take is we take m/2 that is an integer, then if n/2 doesnt belong to integer, the closest one that does is m = n - 1;
then it looks like (m/2)*(-1) + n = -m/2 + 2n/2 = (2n - m)/2 = (2n - n +1)/2 = (n+1)/2 and there, with either possibilties having equal possibilites we take the average value, which is
[(-n/2) + (n +1)/2]/2 = 1/2/2 = 1/4;
-n + n is 0, so wheres your point? how could it possibly give 1/4 ? :)