Added Treap class and test for the same

Author: ShreeHarish

src/test/java/com/thealgorithms/datastructures/trees/TreapTest.java

@@ -0,0 +1,69 @@
+package com.thealgorithms.datastructures.trees;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class TreapTest {
+
+    @Test
+    void arrayBuild() {
+        int[] arr = {5, 9, 6, 2, 3, 8, 1};
+        Treap treap = new Treap(arr);
+        assertEquals("{1,2,3,5,6,8,9,}", treap.inOrder());
+    }
+
+    @Test
+    void build() {
+        Treap treap = new Treap();
+        treap.insert(4);
+        treap.insert(5);
+        treap.insert(9);
+        treap.insert(2);
+        assertEquals("{2,4,5,9,}", treap.inOrder());
+    }
+
+    @Test
+    void delete() {
+        int[] arr = {5, 9, 6, 2, 3, 8, 1};
+        Treap treap = new Treap(arr);
+        treap.delete(5);
+        assertEquals("{1,2,3,6,8,9,}", treap.inOrder());
+    }
+
+    @Test
+    void searchAndFound() {
+        int[] arr = {5, 9, 6, 2, 3, 8, 1};
+        Treap treap = new Treap(arr);
+        assertEquals(5, treap.search(5).value());
+    }
+
+    @Test
+    void searchAndNotFound() {
+        int[] arr = {5, 9, 6, 2, 3, 8, 1};
+        Treap treap = new Treap(arr);
+        assertEquals(null, treap.search(4));
+    }
+
+    @Test
+    void lowerBound() {
+        int[] arr = {5, 9, 6, 2, 3, 8, 1};
+        Treap treap = new Treap(arr);
+        assertEquals(5, treap.lowerBound(4));
+    }
+
+    @Test
+    void upperBound() {
+        int[] arr = {5, 9, 6, 2, 3, 8, 1};
+        Treap treap = new Treap(arr);
+        assertEquals(6, treap.upperBound(5));
+    }
+
+    @Test
+    void misc() {
+        int[] arr = {5, 9, 6, 2, 3, 8, 1};
+        Treap treap = new Treap(arr);
+        assertEquals(7, treap.size());
+        assertEquals(false, treap.isEmpty());
+    }
+}