Binary Search Program in C++ (Iterative)
C++
// C++ program to implement // iterative Binary Search #include <bits/stdc++.h> using namespace std; // Iretative Binary Search function to find the index of an // element 'x' in a sorted array 'arr' if elements is // present, otherwise it return -1 // low: The index of the first element in the current // sub-array high: The index of the last element in the // current sub-array int binarySearch(int arr[], int low, int high, int x) { while (low <= high) { int mid = low + (high - low) / 2; // If the middle element is equal to 'x', we have // found the element, return its index if (arr[mid] == x) return mid; // If the middle element is smaller than 'x', search // in the right half of the array if (arr[mid] < x) low = mid + 1; // If the middle element is greater than 'x', search // in the left half of the array else high = mid - 1; } // If the base case is reached, the element is not // present in the array, return -1 return -1; } // Driver code int main(void) { int arr[] = { 2, 3, 4, 10, 40 }; // Element to be searched int x = 10; int n = sizeof(arr) / sizeof(arr[0]); int result = binarySearch(arr, 0, n - 1, x); (result == -1) ? cout << "Element is not present in array" : cout << "Element is present at index " << result; return 0; } |
Output
Element is present at index 3
Complexity Analysis
- Time Complexity : O(log n)
- Auxiliary Space : O(1)
Please refer complete article on Binary Search for a better understanding.
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C++ Program For Binary Search
In this article, we will learn about the Binary Search algorithm and how to implement it in a C++ program.
Binary Search is a search algorithm that is faster than the linear search algorithm. Binary Search is used to search the position of the target element in a sorted array by repeatedly dividing the search space in half. Binary search eliminates half portion of the array with each comparison. It works in a time complexity of O(log n) where n is the number of elements in the array.
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