ZOJ Problem Set - 3329
There is a very simple and interesting one-person game. You have 3 dice, namely Die1, Die2 and Die3. Die1 has K1 faces. Die2 has K2 faces. Die3 has K3 faces. All the dice are fair dice, so the probability of rolling each value, 1 to K1, K2, K3 is exactly 1 / K1, 1 / K2 and 1 / K3. You have a counter, and the game is played as follow:
Calculate the expectation of the number of times that you cast dice before the end of the game.
There are multiple test cases. The first line of input is an integer T (0 < T <= 300) indicating the number of test cases. Then T test cases follow. Each test case is a line contains 7 non-negative integers n, K1, K2, K3, a, b, c (0 <= n <= 500, 1 < K1, K2, K3 <= 6, 1 <= a <= K1, 1 <= b <= K2, 1 <= c <= K3).
For each test case, output the answer in a single line. A relative error of 1e-8 will be accepted.
2 0 2 2 2 1 1 1 0 6 6 6 1 1 1
Author: CAO, Peng
Source: The 7th Zhejiang Provincial Collegiate Programming Contest