Possible Sample Answer to be Reconsidered?

by Will
(TN)

Is it possible that the sample question's answer is wrong in the way it is worked out?

what in the logic of lines 70 to 130 force the comparison to be between the first item and the next highest number?

it seems that when the value of I changes that the value of No(I) is changed and the value of NO(I-1) is also changed

So what am I missing here if the first comparison is between

4 as NO(I) and 5 as NO(I-1)
after the replacement then
the values are also changed so that now it is
4 , 5

then the value of I is increased by 1 to 3

so then next time through I would think that it would be comparing 1 as NO(I) I being 3
and 5 as NO(I-1)