sorting , binary search, order agnostic searching

ORDER AGNOSTIC BINARY SEARCH/OrderAgniosticSearch.java

@@ -0,0 +1,59 @@
+package dsa;
+
+class OrderAgnosticSearch {
+    public static void main(String[] args) {
+
+        int[] arr = {-18, -12, -4, 0, 2, 3, 4, 15, 16, 18, 22, 45, 89};
+        int target = 22;
+        int ans = orderAgnosticBS(arr, target);
+        System.out.println(ans);
+
+    }
+
+    static int orderAgnosticBS(int[] arr, int target) {
+        int start = 0;
+        int end = arr.length - 1;
+
+
+        // find whether the array is sorted in ascending or descending
+        boolean isAsc = arr[start] < arr[end];
+
+
+        while (start <= end) {
+            //find mid element
+//            int mid = (start + end)/2;                   // might be possible that (start + end) exceed the range of integer java
+            int mid = start + (end - start) / 2;
+
+
+            if (arr[mid] == target) {
+                return mid;
+            }
+
+            if (isAsc) {
+
+
+
+                if (target < arr[mid]) {
+                    end = mid - 1;
+                } else{
+                    start = mid + 1;
+                }
+
+            }
+            else
+            {
+                if (target > arr[mid]) {
+                    end = mid - 1;
+                } else{
+                    start = mid + 1;
+                }
+
+
+            }
+        }
+
+        return -1;
+    }
+
+
+}

binary search in array/binarysearch.java

@@ -0,0 +1,37 @@
+package dsa;
+
+public class binarysearch {
+    public static void main(String[] args) {
+
+        int[] arr = {-18, -12, -4, 0, 2, 3, 4, 15, 16, 18, 22, 45, 89};
+        int target = 22;
+        int ans = binarySearch(arr, target);
+        System.out.println(ans);
+
+
+    }
+
+
+    static int binarySearch(int[] arr, int target) {
+        int start = 0;
+        int end = arr.length - 1;
+
+        while (start <= end) {
+            int mid = start + (end - start) / 2;
+
+            if (target < arr[mid]) {
+                end = mid - 1;
+            } else if (target > arr[mid]) {
+                start = mid + 1;
+            } else {
+                // ans found
+                return mid;
+            }
+
+
+        }
+        return -1;
+    }
+}
+
+

sortingInAnArray/sortingInJava.java

@@ -0,0 +1,36 @@
+package dsa;
+import java.util.Scanner;
+public class sortingInJava
+{
+    public static void main(String[] args)
+    {
+        int n, temp;
+        Scanner s = new Scanner(System.in);
+        System.out.print("Enter the number of elements: ");
+        n = s.nextInt();
+        int a[] = new int[n];
+        System.out.println("Enter the elements of the array: ");
+        for (int i = 0; i < n; i++)
+        {
+            a[i] = s.nextInt();
+        }
+        for (int i = 0; i < n; i++)
+        {
+            for (int j = i + 1; j < n; j++)
+            {
+                if (a[i] < a[j])
+                {
+                    temp = a[i];
+                    a[i] = a[j];
+                    a[j] = temp;
+                }
+            }
+        }
+        System.out.println("Array elements in descending order:");
+        for (int i = 0; i < n - 1; i++)
+        {
+            System.out.println(a[i]);
+        }
+        System.out.print(a[n - 1]);
+    }
+}