$($a$)$ Write the method reverseArray, whose header is given below. The reverseArray method rearranges the elements in arr so that they are in reverse order. For example, the result of reverseArray $($arr$)$ is illustrated below.

Before call to reverseArray $($arr$)$

After call to reverseArray $($arr$)$

Complete the reverseArray method below the following header.

$//$ postcondition: elements of arr are reversed public static void reverseArray $($int$[]$ arr$)$

$($b$)$ Write the method reversevertical, whose header is given below. The reversevertical method rearranges the elements of one column of the two$-$dimensional array $m$ so that they are in reverse order. For example, the result of reversevertical $(m,2),$ is illustrated below.

Before call to reversevertical $(m,2)$

After call to reverseVertical $(m,2)$

Complete the method reverseVertical below the following header.

$//$ precondition: $mmm0$col. length$\frac{?}{\frac{?}{?}}$

the number $of$ rows $inmism.$ length

public static void reverseVertical $(int[][]m,$ int col$)$