c programming language

4) Define an array with 20 elements. a) Input the values of array by keyboard ( 5 P) b) Find the number of positive elements and print the number of positive elements. (5 P) c) Find the number of negative elements and print the number of negative elements. (5 P) d) Find the maximum nefgative element in array. (Note: Think that the 0th element is a positive) (10 P)