Write a C program that asks the user to enter 15 integer
numbers and then store them in the array. Then, the program will
find the second largest element in array and its index without
sorting the array. For example, In this array {-55,-2,1, 2, -3, 0,
5, 9, 13, 1, 4, 3, 2, 1, 0}, the second largest element is 9 [found
at index 7].