How to put zero logic over here?

#1

I can’t understand how to do this problem after this

#2

Hey @yobasu2015
The logic behind this Problem was pretty simple as we can invert any digit ( 9 - digit) but we need to invert only such digits that will eventually end up giving the smallest number possible.

So, we should invert only digits greater then or equal to 5 as after inverting them, the result gives us smallest number.

For e.g.,

9 - 5 = 4 viz, smaller than the original number that was 5.

9 - 8 = 1 viz, smaller than the original number that was 8.

but 9 - 1 = 8 viz, greater than the original number that was 1.

Important point to consider is, After inverting any digits there should not be any zeroes in the starting, that means, if there is 9 at the starting of the number then it must remain the same