Pirate Crew

Two Pirates $i$ and $j$ can see each other if there are no taller Pirates standing between them. Formally, Pirates $i$ and $j$ (i < j) can see each other if for each integer k (i<k<j), hk≤hi≤hj. There are $N$ Pirates standing in a queue to get some food from the Pirate chef, numbered $1$ to $N$ from left to right. For each valid $i$, the $i-th$ Pirate has a height $hi$. For each valid $i$, dete