A problem asks to count the number of ordered sets of 4 numbers that sum up to 10, here ordered means either the sequence is increasing where each next element is either greater or equal to the previous, or decreasing, where each element is less or equal to the previous?

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TopNewestOrdered set refers to the order in which the elements appear. For example, the ordered set ( Alvin, Calvin, 501) is different from the ordered set (501, Alvin, Calvin). It has nothing to do with the order of the elements of the set, since we may not presume that the elements have a natural ordering. – Calvin Lin Staff · 4 years, 5 months ago

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– Ervin Kamberoski · 4 years, 5 months ago

Not sure this makes it clearer.Log in to reply