MONEY: question unclear

In this Money problem I am confused as to which are the valid sets and which are invalid…
Can someone provide me with valid sets for 10…??

where is question? any link.?

this is the link:

I think you are talking about this problem http://www.codechef.com/problems/MONEY, and in that problem, a " valid set for an integer(money) N is set of integers(currency notes) by which we can make each sum (1 to N) by choosing some of the integers. And each sum (1 to N) can only be made by one way". Examples are clearly given in problem. As this is a recruitment question of Directi so can’t write more.

Just explain this:
Given:-
Invalid sets are
{1,1,1,2,2} beacuse the sum adds up to 7 but 2 can be made by {1,1} and {2}, 3 can be made by {1,1,1} and {1,2}, 4 can be made by {1,1,2} and {2,2}

then why is {1,2,2,2} a valid set since {1,2} adds to 3, {2,2} adds to 4 etc.

and what do u mean that it is a recruitment question…??

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