3-3 write a function that given an array and its length, returns the weighted average of the array, defined as x . win where x represents all the distinct elements in the array, w, represents how many times the value of element x, appears in the array, and n is the size of the array. eg. if the array is (1,2,1,4.1,3 the weighted average is (1 . 3 / 6) + (21/6) + (1-3/6)+(41/6) + (1-3/6) + (31/6)-3.0. The function must return 0 if the size parameter, n, is less than 1. Signature: double welghtedaverage(int arrayll, int n)