Merge pull request #4 from rajiyasultana/master

Binary search in a sorted array

Binary_Search.cpp

@@ -0,0 +1,62 @@
+#include<iostream>
+using namespace std;
+
+/* Function to perform binary search in a sorted array
+ Parameters:
+ - arr: Sorted array to be searched
+ - n: Size of the array
+ - key: Element to be searched for
+ Returns:
+ - Index of the key if found, otherwise -1*/
+
+int binarysearch(int arr[], int n, int key)
+{
+    int start = 0;  // Initialize the starting index of the search range
+    int end = n;    // Initialize the ending index of the search range
+
+    // Continue the search until the start index is less than or equal to the end index
+    while (start <= end)
+    {
+        int mid = (start + end) / 2;  // Calculate the middle index
+
+        if (arr[mid] == key)  // Check if the middle element is equal to the key
+        {
+            return mid;  // Return the index where the key is found
+        }
+        else if (arr[mid] < key)  // If key is greater, update the start index
+        {
+            start = mid + 1;
+        }
+        else  // If key is smaller, update the end index
+        {
+            end = mid - 1;
+        }
+    }
+
+    // If key is not found in the array, return -1
+    return -1;
+}
+
+int main()
+{
+    int n;
+    cout << "Enter the array size: ";
+    cin >> n;
+
+    int arr[n];
+    cout << "Enter the elements of the array in sorted order: ";
+    for(int i = 0; i < n; i++)
+    {
+        cin >> arr[i];
+    }
+
+    int key;
+    cout << "Enter the key: " ;
+    cin >> key;
+
+    // Call the binarysearch function and output the result
+    cout << "The key is found at position: " << binarysearch(arr, n, key) << endl;
+
+    // Return 0 to indicate successful execution
+    return 0;
+}