#P7633. [2018年杭电多校]Rikka with Stone-Paper-Scissors
[2018年杭电多校]Rikka with Stone-Paper-Scissors
Rikka with Stone-Paper-Scissors
Problem Description
Did you watch the movie "Animal World"? There is an interesting game in this movie. The rule is like traditional Stone-Paper-Scissors. At the beginning of the game, each of the two players receives several cards, and there are three types of cards: scissors, stone, paper. And then in each round, two players need to play out a card simultaneously. The chosen cards will be discarded and can not be used in the remaining part of the game. The result of each round follows the basic rule: Scissors beat Paper, Paper beats Stone, Stone beats Scissors. And the winner will get point, the loser will lose point, and the points will not change in the case of a draw. Now, Rikka is playing this game with Yuta. At first, Yuta gets Scissors cards, Stone cards and Paper cards; Rikka gets Scissors cards, Stone cards, Paper cards. The parameters satisfy . And then they will play the game exactly rounds (i.e., they will play out all the cards). Yuta's strategy is "random". Each round, he will choose a card among all remaining cards with equal probability and play it out. Now Rikka has got the composition of Yuta's cards (i.e., she has got the parameters ) and Yuta's strategy (random). She wants to calculate the maximum expected final points she can get, i.e., the expected final points she can get if she plays optimally. Hint: Rikka can make decisions using the results of previous rounds and the types of cards Yuta has played.
Input
The first line contains a single number . For each testcase, the first line contains three numbers and the second line contains three numbers $a',b',c'(0 \leq a,b,c,a',b',c' \leq 10^9, a+b+c =a' + b' + c'> 0)$.
Output
For each testcase, if the result is an integer, print it in a line directly. Otherwise, if the result equals to and are integers, output "/" (without the quote) in a single line.
Sample Input
4
2 0 0
0 2 0
1 1 1
1 1 1
1 0 0
0 0 1
123 456 789
100 200 1068
Sample Output
2
0
-1
3552/19
Source
2018 Multi-University Training Contest 9