Cut the cake
Time Limit: 2000/1000 MS (Java/others) memory limit: 32768/32768 K (Java/Others)
Total submission (s): 885 accepted submission (s): 432
Problem descriptionmmm got a big cake, and invited all her m friends to eat the cake together. surprisingly one of her friends Hz took some (n) strawberries which Mmm likes very much to decorate the cake (of course they also eat strawberries, not just for decoration ). hz is in charge of the decoration, and he thinks that it's not a big deal that he put the strawberries on the cake randomly One by one. after that, mmm wocould cut the cake into M pieces of sector with equal size and shape (the last one came to the party will have no cake to eat), and choose one piece first. mmm wants to know the probability that she can get all N strawberries, can you help her? As the cake is so big, all strawberries on it cocould be treat as points.
Inputfirst line is the integer T, which means there are t cases.
For each case, two integers m, n indicate the number of her friends and the number of strawberry.
(2 <m, n <= 20, T <= 400)
Outputas the probability cocould be very small, you shocould output the probability in the form of a fraction in lowest terms. for each case, output the probability in a single line. please see the sample for more details.
Sample Input
23 33 4
Sample output
1/34/27
Question: N strawberries. Divide the cake into M blocks. The probability that N strawberries are all in one cake
Idea: the formula is N/m ^ (n-1), which can be calculated by multiplication of large numbers.
Hdu4762 (mathematical probability)
