P2973 [USACO10HOL]赶小猪Driving Out the Piggi…
一个无向图，节点1有一个炸弹，在每个单位时间内，有p/q的概率在这个节点炸掉，有1-p/q的概率随机选择一条出去的路到其他的节点上。问最终炸弹在每个节点上爆炸的概率。
输入格式：
* Line 1: Four space separated integers: N, M, P, and Q
* Lines 2..M+1: Line i+1 describes a road with two space separated integers: A_j and B_j
输出格式：
* Lines 1..N: On line i, print the probability that city i will be destroyed as a floating point number. An answer with an absolute error of at most 10^-6 will be accepted (note that you should output at least 6 decimal places for this to take effect).
