Along with other things, Feadagor is fond of playing tabletop role playing games. He has just discovered
a new game and he’d like to play it with his friends. Unluckily, he cannot call his friends right now, as
the game requires quite an unusual set of dice. The description of the game says that there must be
n dice, and i-th die must have ai faces. Each die must be shaped so its faces fall equiprobably.
According to the game manual, the numbers from 1 to m, where m = ∑ai for i = 1 to n, must be written on the
faces, and each number from the interval must be used exactly once. The numbers arrangement must
be chosen so that if you throw all the dice simultaneously, then the mathematical expectation E of the
total value in such experiment will be maximal.
The manual says that only Maiar have enough wisdom to arrange the numbers properly (and therefore
your only choice is to buy the dice just for 133 dollars, telepathy is quite expensive now). But maybe
there is a simpler way to make the proper arrangement?
Warn: 本題有 specialjudge
The input file contains several test cases.
The first line of each test case contains a single integer number n (1 ≤ n ≤ 1000). The following line
contains n integer numbers a1, a2 ... an (1 ≤ ai ≤ 100).
The first line of the output file must contain maximal possible expectation E — a floating-point number
precise up to 5 digits after the decimal point.
The following n lines must contain the numbers arrangement: i-th line must contain ai
integer numbers — the numbers to be written on the faces of i-th die.
2 1 4
7.50000 5 1 2 3 4
Migrated from old NTUJ.
ACM ICPC 2011–2012, NEERC, Northern Subregional Contest
| No. | Testdata Range | Score |
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