Java implementation of interpolation search

search/interpolation_search/Java/InterpolationSearch.java

@@ -0,0 +1,49 @@
+import java.util.Arrays;
+
+public class InterpolationSearch {
+
+    private static final int NOT_FOUND = -1;
+
+    static int interpolationSearch(int[] arr, int x) {
+
+        // Keep track of the two indexes 
+        int lo = 0;
+        int hi = (arr.length - 1);
+
+        while (lo <= hi && x >= arr[lo] && x <= arr[hi]) {
+
+            // Calculate the position to check
+            int pos = lo + (((hi-lo) /
+                    (arr[hi]-arr[lo]))*(x - arr[lo]));
+
+            // The key was found! 
+            if (arr[pos] == x){
+                return pos; 
+            }
+
+            // If x is larger, x is in upper part 
+            if (arr[pos] < x) {
+                lo = pos + 1;
+            }
+
+            // If x is smaller, x is in the lower part 
+            else {
+                hi = pos - 1;
+            }
+        }
+
+        // The key was not found!
+        return NOT_FOUND;
+    }
+
+    // Driver method  
+    public static void main(String[] args)
+    {
+        int key = 18;
+        int[] test = {10, 12, 13, 16, 18, 19, 20, 21, 22, 23, 24, 33, 35, 42, 47};
+        int index = interpolationSearch(test, key);
+        System.out.println("The Sample Array: " + Arrays.toString(test));
+        System.out.println("The Test Key: " + key);
+        System.out.println("The Index Of The Key: " + index);
+    }
+}