delete() for Splay Tree

Author: Kishan-Ved

pydatastructs/trees/_backend/cpp/SplayTree.hpp

@@ -139,9 +139,27 @@ static PyObject* SplayTree_insert(SplayTree *self, PyObject* args) {
     Py_RETURN_NONE;
 }
 
+static PyObject* SplayTree_delete(SplayTree *self, PyObject* args) {
+    PyObject* x = PyObject_GetItem(args, PyZero);
+    BinaryTree* bt = self->sbbt->bst->binary_tree;
+
+    PyObject* kwd_parent = PyDict_New();
+    PyDict_SetItemString(kwd_parent, "parent", PyLong_FromLong(1));
+    PyObject* tup = SelfBalancingBinaryTree_search(self->sbbt, Py_BuildValue("(O)", x), kwd_parent);
+    PyObject* e = PyTuple_GetItem(tup, 0);
+    PyObject* p = PyTuple_GetItem(tup, 1);
+    if (e == Py_None){
+        Py_RETURN_NONE;
+    }
+    SplayTree_splay(self, Py_BuildValue("(OO)", e, p));
+    PyObject* status = SelfBalancingBinaryTree_delete(self->sbbt, Py_BuildValue("(O)", x), PyDict_New());
+    return status;
+}
+
 
 static struct PyMethodDef SplayTree_PyMethodDef[] = {
     {"insert", (PyCFunction) SplayTree_insert, METH_VARARGS, NULL},
+    {"delete", (PyCFunction) SplayTree_delete, METH_VARARGS, NULL},
     {NULL}
 };
 

pydatastructs/trees/tests/test_binary_trees.py

@@ -503,28 +503,28 @@ def test_SplayTree():
     assert [node.key for node in in_order] == [20, 30, 40, 50, 55, 100, 200]
     assert [node.key for node in pre_order] == [55, 30, 20, 40, 50, 200, 100]
 
-    # t.delete(40)
+    t.delete(40)
 
-    # in_order = trav.depth_first_search(order='in_order')
-    # pre_order = trav.depth_first_search(order='pre_order')
-    # assert [node.key for node in in_order] == [20, 30, 50, 55, 100, 200]
-    # assert [node.key for node in pre_order] == [50, 30, 20, 55, 200, 100]
+    in_order = trav.depth_first_search(order='in_order')
+    pre_order = trav.depth_first_search(order='pre_order')
+    assert [node.key for node in in_order] == [20, 30, 50, 55, 100, 200]
+    assert [node.key for node in pre_order] == [50, 30, 20, 55, 200, 100]
 
-    # t.delete(150)
+    t.delete(150)
 
-    # in_order = trav.depth_first_search(order='in_order')
-    # pre_order = trav.depth_first_search(order='pre_order')
-    # assert [node.key for node in in_order] == [20, 30, 50, 55, 100, 200]
-    # assert [node.key for node in pre_order] == [50, 30, 20, 55, 200, 100]
+    in_order = trav.depth_first_search(order='in_order')
+    pre_order = trav.depth_first_search(order='pre_order')
+    assert [node.key for node in in_order] == [20, 30, 50, 55, 100, 200]
+    assert [node.key for node in pre_order] == [50, 30, 20, 55, 200, 100]
 
-    # t1 = SplayTree(1000, 1000)
-    # t1.insert(2000, 2000)
+    t1 = SplayTree(1000, 1000)
+    t1.insert(2000, 2000)
 
-    # trav = BinaryTreeTraversal(t1)
-    # in_order = trav.depth_first_search(order='in_order')
-    # pre_order = trav.depth_first_search(order='pre_order')
-    # assert [node.key for node in in_order] == [1000, 2000]
-    # assert [node.key for node in pre_order] == [2000, 1000]
+    trav = BinaryTreeTraversal(t1)
+    in_order = trav.depth_first_search(order='in_order')
+    pre_order = trav.depth_first_search(order='pre_order')
+    assert [node.key for node in in_order] == [1000, 2000]
+    assert [node.key for node in pre_order] == [2000, 1000]
 
     # t.join(t1)