1. Write the program to implement Binary Search Algorithm in C++. Use the Binary Search Function that takes the array A, the first index (first), the last index (last) and the search key V as inputs, and the function will return the index of the searched key. If the function returns -1 then display a message in main, that the data is not found, but if it returns a non-zero number, then display the index of the searched key. Make sure to supply a sorted array as input from main. You must give your program along with the code outputs.

In this program, we define a function binarySearch that takes an array A, the first index first, the last index last, and the search key V as inputs. The function uses a while loop to repeatedly divide the array in half and compare the middle element to the search key. If the middle element is equal to the search key, the function returns the index of the middle element. If the middle element is less than the search key, the function updates the first index to be the middle index + 1. If the middle element is greater than the search key, the function updates the last index to be the middle index - 1. If the search key is not found in the array, the function returns -1.

In the main function, we create a sorted array A and call the binarySearch function with the first index, last index, and search key. If the function returns -1, we output a message that the data was not found. If the function returns a non-zero number, we output the index of the search key. In this example, the search key is 18, and the function should return the index 6.