Problem $4.$ You are given an unsorted array $\backslash ($ A$[1$: n$]\backslash )$ of n distinct positive integers. Design an algorithm that in $\backslash ($ O$($n$)\backslash )$ worst$-$case time, where M is the maximum possible integer within A finds the h$-$index of A$.$ The h $-$index is defined as the maximum integer h such that $\backslash ($ A$[1$: n$]\backslash )$ has at least h indices whose entry is at least h$.$