Regarding the code

#1

why we are doing -1 ???

as earlier lecture using upper bound we are getting exact index

#2

There’s no need to do it as you have added your comp function to handle the case moreover if there is any doubt in this ? feel free to ask.

I can’t find any video in which money change problem is being explained using upper bound. Tell me the name of the video if there is any, so that i can help you.

#3

but sir in the video of money change we are doing -1 though we have already use the comparator

#4

See this


We are doing -1 because array index starts from zero
Moreover when you we will do this

lower_bound(arr,arr+5,8,compare)

Then if you don’t subtract -1 you will get 0, and arr[0] is 10. Which we don’t want. But when you do -1 then your result will be -1, as no coin for this result.

#5

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