binary-search.py

from typing import List

def binary_search(numbers: List[int], target: int) -> bool:
    """
    Perform binary search to check if the target exists in the sorted list.

    :param numbers: A sorted list of integers.
    :param target: The integer to search for.
    :return: True if the target exists, False otherwise.
    """
    start = 0
    end = len(numbers) - 1

    while start <= end:
        mid = (start + end) // 2
        if target == numbers[mid]:
            # Target found at the middle index.
            return True
        elif target < numbers[mid]:
            # Target is in the left half.
            end = mid - 1
        else:  # target > numbers[mid]
            # Target is in the right half.
            start = mid + 1

    # Target not found.
    return False

BinarySearch.cs

static int BinarySearch(IReadOnlyList<int> array, int target)
{
    // Initialize left and right pointers for the binary search
    int left = 0;
    int right = array.Count - 1;

    // Continue the search until the left pointer exceeds the right pointer
    while (left <= right)
    {
        // Calculate the middle index
        int mid = left + (right - left) / 2;

        // Check if the middle element is the target
        if (array[mid] == target)
        {
            // Target found, return the index
            return mid;
        }

        // If the target is greater than the middle element, search the right half
        if (array[mid] < target)
        {
            left = mid + 1;
        }
        // If the target is smaller than the middle element, search the left half
        else
        {
            right = mid - 1;
        }
    }

    // Target not found in the array
    return -1;
}