Add exponential search algorithm

Author: vieriloh

src/main/java/com/thealgorithms/searchs/ExponentialSearch.java

@@ -0,0 +1,48 @@
+package com.thealgorithms.searchs;
+
+import java.util.Arrays;
+
+public class ExponentialSearch {
+    // Exponential Search algorithm
+    public static int exponentialSearch(int[] arr, int x) {
+        int n = arr.length;
+
+        // If the element is present at the first position
+        if (arr[0] == x) return 0;
+
+        // Find the range for binary search by repeated doubling
+        int i = 1;
+        while (i < n && arr[i] <= x) {
+            i = i * 2;
+        }
+
+        // Do binary search in the found range
+        return binarySearch(arr, x, i / 2, Math.min(i, n - 1));
+    }
+
+    // Binary Search algorithm
+    private static int binarySearch(int[] arr, int x, int low, int high) {
+        while (low <= high) {
+            int mid = low + (high - low) / 2;
+
+            if (arr[mid] == x) return mid;
+
+            if (arr[mid] < x) low = mid + 1;
+            else high = mid - 1;
+        }
+        return -1; // Element not found
+    }
+
+    public static void main(String[] args) {
+        int[] arr = {1, 3, 5, 7, 9, 11, 15, 17, 19, 21};
+        int x = 15;
+
+        int result = exponentialSearch(arr, x);
+
+        if (result == -1) {
+            System.out.println("Element not found.");
+        } else {
+            System.out.println("Element found at index " + result);
+        }
+    }
+}