my submission link

there are too many wa’s.

What have i done

i make 2d dp array in which dp[i][j] denote if i start at index i and I need to have atleast k

heads 's answer

and i write some recurisive function with base cases

first case if the remaining elements are less than required heads i will simply return 0

second case if i have traversed all array then returning 1 means nothing can be done

and main logic

dp[i][j] = head*(index+1,count-1) + tails(index+1,count)

head is probability of heads coming same with tails and count denote how much required

UPD:: I solved it using itereative method still looking for mistake in recursive version and i made a change in value of k = (n/2) + 1 i was missing for even sized array