Question

Write a function that takes a sorted list and a number as an argument. Search for the number in the sorted list using binary search.

Answer 1

Binary search compares the required number with the middle element and searches only the appropriate half of the sorted list.

def binary_search(data_list, number):
    low = 0
    high = len(data_list) - 1

    while low <= high:
        mid = (low + high) // 2

        if data_list[mid] == number:
            return mid + 1  # Return 1-based position
        if data_list[mid] < number:
            low = mid + 1
        else:
            high = mid - 1

    return -1


numbers = [2, 6, 7, 10, 14, 15, 16, 19]
position = binary_search(numbers, 14)

if position == -1:
    print("Element not found")
else:
    print("Element found at position", position)

Element found at position 5