You have some coins. The i-th coin has a probability prob[i] of facing heads when tossed.
Return the probability that the number of coins facing heads equals target if you toss every coin exactly once.
Example 1:
Input: prob = [0.4], target = 1 Output: 0.40000
Example 2:
Input: prob = [0.5,0.5,0.5,0.5,0.5], target = 0 Output: 0.03125
Constraints:
1 <= prob.length <= 10000 <= prob[i] <= 10 <= target<= prob.length- Answers will be accepted as correct if they are within
10^-5of the correct answer.