Puolitusetsintä

Puolitusetsintä, also known as binary search, is a highly efficient searching algorithm used to find the position of a target value within a sorted array. It works by repeatedly dividing the search interval in half. The algorithm starts by comparing the target value with the middle element of the array. If the target value matches the middle element, its position is found. If the target value is less than the middle element, the search continues in the left half of the array. If the target value is greater than the middle element, the search continues in the right half of the array. This process of halving the search space is repeated until the target value is found or the interval becomes empty, indicating that the target value is not present in the array.

The efficiency of puolitusetsintä stems from its logarithmic time complexity, denoted as O(log n), where 'n' is the number of elements in the array. This means that the number of comparisons required grows very slowly with the size of the array, making it significantly faster than linear search for large datasets. For puolitusetsintä to function correctly, the input array must be sorted in ascending or descending order. If the array is not sorted, the algorithm will likely produce incorrect results or fail to find the target value even if it exists. This algorithm is a fundamental concept in computer science and has numerous applications in data retrieval and sorting.