Create a Matlab function file, whose input is a $2$D array. The function does the following:

a$.$

Find the maximal value of all entries of the input array.

b$.$

Count the number of entries with values $>128.$

c$.$ For each entry of the input array, if its value is $>128,$ change its value to $255.$

Otherwise change its value to $0.$ Assign the result to a new array.

d$.$ The function should return the results of steps a$,$ b above, as well as the modified array in c$.$