From 66c15bc5f513e9ea04a1a7c1956c140f804c95a1 Mon Sep 17 00:00:00 2001
From: Leo <neotheone458@gmail.com>
Date: Wed, 31 May 2023 16:20:52 +0530
Subject: [PATCH] added java code for Algorithm no.79

---
 .../Order_Agnostic_Binary_Search.java         | 107 ++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 Java/Searching/Order_Agnostic_Binary_Search.java

diff --git a/Java/Searching/Order_Agnostic_Binary_Search.java b/Java/Searching/Order_Agnostic_Binary_Search.java
new file mode 100644
index 000000000..c30c77276
--- /dev/null
+++ b/Java/Searching/Order_Agnostic_Binary_Search.java
@@ -0,0 +1,107 @@
+/*
+PROBLEM STATEMENT : Perform an order-agnostic binary search on a sorted array. The only way it is different from a regular binary search is that we don't know whether the array is sorted in sorted in descending or ascending order.
+
+INPUT FROM USER :
+ * arr -> The sorted array to search in.
+ * n -> The total number of elements inside the array.
+ * key -> The value to search for.
+
+OUTPUT :
+* Print the index of the key value in the array if found, -1 otherwise. 
+
+
+PREREQUISITE : The function assumes that the input array is sorted in either ascending or descending order. If the array is not sorted , the program may not produce correct results.
+
+COMPLEXITY :
+*Time Complexity : O(log(n))
+*Space Complexity : O(1)
+
+PSEUDOCODE :
+1. Input the array from the user.
+2. Input the key to be searched inside the array.
+3. Call the function order_agnostic_binary_search() with the array, size of the array and the key as the parameters.
+4. The function order_agnostic_binary_search() will determine whether the array is sorted in ascending or descending order and then call the appropriate function for each case.
+5.(A) The function ascending_binary_search() will perform binary search on the array if it is sorted in ascending order.
+5.(B) The function descending_binary_search() will perform binary search on the array if it is sorted in descending order.
+6. Store the result returned by the function order_agnostic_binary_search() in a variable 'result'.
+7. If the value of 'result' is -1, print "Target value not found in the array.".
+8. Else print the index at which the key to search for is found in the array.
+*/
+
+import java.util.Scanner;
+
+public class Order_Agnostic_Binary_Search {
+    public static int orderAgnosticBinarySearch(int[] arr, int target) {
+        // Determine the order (ascending or descending) based on the first two elements
+        boolean isAscending = arr[0] <= arr[1];
+
+            if (isAscending) {
+                return ascending_binary_search(arr, target);
+            } else {
+                return descending_binary_search(arr, target);
+            }
+    }
+
+    public static int ascending_binary_search(int[] arr, int target){
+        int left = 0;
+        int right = arr.length - 1;
+        while(left <= right){
+            int mid = left + (right-left)/2;
+            if(arr[mid] == target){
+                return mid;
+            }
+            else if(arr[mid] < target){
+                left = mid + 1;
+            }
+            else{
+                right = mid - 1;
+            }
+        }
+        return -1; // Target value not found in the array
+    }
+
+    public static int descending_binary_search(int[] arr, int target){
+        int left = 0;
+        int right = arr.length - 1;
+        while(left <= right){
+            int mid = left + (right-left)/2;
+            if(arr[mid] == target){
+                return mid;
+            }
+            else if(arr[mid] > target){
+                left = mid + 1;
+            }
+            else{
+                right = mid - 1;
+            }
+        }
+        return -1; // Target value not found in the array
+    }
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("Enter the size of the array: ");
+        int size = scanner.nextInt();
+
+        int[] arr = new int[size];
+        System.out.println("Enter the array elements in sorted order:");
+        for (int i = 0; i < size; i++) {
+            arr[i] = scanner.nextInt();
+        }
+
+        System.out.print("Enter the target value to search: ");
+        int target = scanner.nextInt();
+
+
+        int result = orderAgnosticBinarySearch(arr, target);
+
+        if (result == -1) {
+            System.out.println("Target value not found in the array.");
+        } else {
+            System.out.println("Target value found at index: " + result);
+        }
+
+        scanner.close();
+    }
+}
+