Add orderAgnosticBinarySearch (TheAlgorithms#3882)

SunilKumar-K · siriak · web-flow · commit 6b9eb1b9c1ed · 2023-02-23T17:19:05.000Z
Co-authored-by: Andrii Siriak &lt;siryaka@gmail.com&gt;
diff --git a/src/main/java/com/thealgorithms/searches/sortOrderAgnosticBinarySearch.java b/src/main/java/com/thealgorithms/searches/sortOrderAgnosticBinarySearch.java
@@ -0,0 +1,32 @@
+package com.thealgorithms.searches;
+import java.util.*;
+public class sortOrderAgnosticBinarySearch {
+    public static int find(int arr[],int key){
+        int start = 0;
+        int end = arr.length-1;
+        boolean arrDescending = arr[start]>arr[end];  //checking for Array is in ascending order or descending order.
+        while(start<=end){
+            int mid = end-start/2;
+            if (arr[mid]==key){
+                return mid;
+            }
+            if(arrDescending){       // boolean is true then our array is in descending order 
+                if(key<arr[mid]){
+                    start=mid+1;
+                }
+                else{
+                    end=mid-1;
+                }
+            }
+            else {         // otherwise our array is in ascending order 
+                if(key>arr[mid]){
+                   start=mid+1;
+               }
+               else{
+                   end=mid-1;
+               }
+            }
+        }
+        return -1;
+    }
+}
diff --git a/src/test/java/com/thealgorithms/searches/sortOrderAgnosticBinarySearchTest.java b/src/test/java/com/thealgorithms/searches/sortOrderAgnosticBinarySearchTest.java
@@ -0,0 +1,27 @@
+package com.thealgorithms.searches;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class sortOrderAgnosticBinarySearchTest{
+
+    @Test
+    public void testAscending(){
+        int arr[] = {1,2,3,4,5};// for ascending order.
+        int target = 2;
+        int ans=sortOrderAgnosticBinarySearch.find(arr, target);
+        int excepted = 1;
+        assertEquals(excepted,ans);
+    }
+
+    @Test
+    public void testDescending(){
+        int arr[] = {5,4,3,2,1};// for descending order.
+        int target = 2;
+        int ans=sortOrderAgnosticBinarySearch.find(arr, target);
+        int excepted = 3;
+        assertEquals(excepted,ans );
+    }
+
+}
