Write a C++ function, smallestindex, that takes as parameters an int array and its size and returns the index of the first occurrence of the smallest element in the array. Also, write a program to test your function. /* Write a C++ function, smallestIndex, that takes as parameters an int array and its size (int), and returns the index of the smallest element in the array (int). The function prototype is int smallestIndex( int arr[], int size); Also, write a program to test the function to print the value of the smallest index. */