Finish implementing insert and delete functions

diff --git a/source/list/sll.c b/source/list/sll.c
index f0300d7c7ccf66490021a263b226587684cc69d7..fa2a8de2425377f85d7e49390ed8129ed9ff25f2 100644 (file)
--- a/source/list/sll.c
+++ b/source/list/sll.c
@@ -181,25 +181,22 @@ sll_node_t* sll_pop_back( sll_t* list )
 sll_node_t* sll_insert( sll_t* list, unsigned int index, void* contents)
 {
     sll_node_t* new_node = NULL;
-    if( NULL == list )
+    if( 0 == index )
     {
-        if( 0 == index )
-        {
-            new_node = sll_push_front( list, contents );
-        }
-        else
+        new_node = sll_push_front( list, contents );
+    }
+    else
+    {
+        sll_node_t* prev_node = sll_index( list, index - 1 );
+        if( NULL != prev_node )
         {
-            sll_node_t* prev_node = sll_index( list, index - 1 );
-            if( NULL == prev_node )
+            sll_node_t* next_node = prev_node->next;
+            new_node = sll_new_node( contents );
+            new_node->next = next_node;
+            prev_node->next = new_node;
+            if( NULL == next_node )
             {
-                sll_node_t* next_node = prev_node->next;
-                new_node = sll_new_node( contents );
-                new_node = next_node;
-                prev_node->next = new_node;
-                if( NULL == next_node )
-                {
-                    list->tail = new_node;
-                }
+                list->tail = new_node;
             }
         }
     }
@@ -208,8 +205,33 @@ sll_node_t* sll_insert( sll_t* list, unsigned int index, void* contents)
 
 sll_node_t* sll_delete( sll_t* list, unsigned int index, int free_contents)
 {
-    sll_node_t* new_node = NULL;
+    sll_node_t* node = NULL;
 
-    return new_node;
+    if (0 == index)
+    {
+        node = sll_pop_front(list);
+        if (NULL != node)
+        {
+            sll_free_node(node,free_contents);
+            node = sll_front(list);
+        }
+    }
+    else
+    {
+        sll_node_t* prev = sll_index(list,index-1);
+        node = (NULL == prev) ? NULL : prev->next;
+        if (NULL != node)
+        {
+            prev->next = node->next;
+            if (NULL == prev->next)
+            {
+                list->tail = prev;
+            }
+            sll_free_node(node,free_contents);
+            node = prev->next;
+        }
+    }
+
+    return node;
 }
 

diff --git a/tests/test_sll.cpp b/tests/test_sll.cpp
index 2c014ff7f4e79db50d0db52babfe4c6d2c83f8a0..c9d9c65d5dc54f413d85a28936380f25312f0f80 100644 (file)
--- a/tests/test_sll.cpp
+++ b/tests/test_sll.cpp
@@ -372,11 +372,123 @@ namespace {
         CHECK( NULL == sll_insert( NULL, 0, (void*)0x1234 ) );
     }
 
+    TEST(Verify_insert_should_insert_into_empty_list)
+    {
+        sll_t list = { NULL, NULL };
+        sll_node_t* node = sll_insert( &list, 0, (void*)0x1234 );
+        CHECK( node != NULL );
+        CHECK( node->next == NULL );
+        CHECK( node->contents == (void*)0x1234 );
+        CHECK( list.head == node );
+        CHECK( list.tail == node );
+    }
+
+    TEST(Verify_insert_should_push_to_the_front_of_the_list_if_index_is_0)
+    {
+        sll_node_t node1 = { NULL, NULL };
+        sll_t list = { &node1, &node1 };
+        sll_node_t* node = sll_insert( &list, 0, (void*)0x1234 );
+        CHECK( NULL != node );
+        CHECK( (void*)0x1234 == node->contents );
+        CHECK( NULL != node->next );
+        CHECK( node == list.head );
+        CHECK( node != list.tail );
+    }
+
+    TEST(Verify_insert_should_insert_at_the_given_index_if_index_is_non_zero)
+    {
+        sll_node_t node3 = { NULL, NULL };
+        sll_node_t node2 = { NULL, &node3 };
+        sll_node_t node1 = { NULL, &node2 };
+        sll_t list = { &node1, &node3 };
+        sll_node_t* node = sll_insert( &list, 1, (void*)0x1234 );
+        CHECK( NULL != node );
+        CHECK( (void*)0x1234 == node->contents );
+        CHECK( node1.next == node );
+        CHECK( &node2 == node->next );
+    }
+
+    TEST(Verify_insert_should_set_the_tail_of_the_list_if_index_is_the_last_item)
+    {
+        sll_node_t node2 = { NULL, NULL };
+        sll_node_t node1 = { NULL, &node2 };
+        sll_t list = { &node1, &node2 };
+        sll_node_t* node = sll_insert( &list, 2, (void*)0x1234 );
+        CHECK( NULL != node );
+        CHECK( (void*)0x1234 == node->contents );
+        CHECK( NULL == node->next );
+        CHECK( node2.next == node );
+        CHECK( list.tail == node );
+    }
+
+    TEST(Verify_insert_should_return_null_if_index_out_of_range)
+    {
+        sll_node_t node2 = { NULL, NULL };
+        sll_node_t node1 = { NULL, &node2 };
+        sll_t list = { &node1, &node2 };
+        sll_node_t* node = sll_insert( &list, 3, (void*)0x1234 );
+        CHECK( NULL == node );
+    }
+
     //-------------------------------------------------------------------------
     // Test sll_delete function
     //-------------------------------------------------------------------------
     TEST(Verify_delete_does_nothing_if_list_is_null)
     {
-        CHECK( NULL == sll_insert( NULL, 0, 0 ) );
+        CHECK( NULL == sll_delete( NULL, 0, 0 ) );
+    }
+
+    TEST(Verify_delete_does_nothing_if_list_is_empty)
+    {
+        sll_t list = { NULL, NULL };
+        CHECK( NULL == sll_delete( &list, 0, 0 ) );
+    }
+
+    TEST(Verify_delete_deletes_the_first_element_of_a_list_of_length_1)
+    {
+        sll_node_t* node = sll_new_node((void*)0x1234);
+        sll_t list = { node, node };
+        CHECK( NULL == sll_delete( &list, 0, 0 ) );
+        CHECK( list.head == NULL );
+        CHECK( list.tail == NULL );
+    }
+
+    TEST(Verify_delete_deletes_the_first_element_of_a_list_of_length_2)
+    {
+        sll_node_t* node1 = sll_new_node((void*)0x1234);
+        sll_node_t  node2 = { (void*)0x1234, NULL };
+        node1->next = &node2;
+        sll_t list = { node1, &node2 };
+        sll_node_t* node = sll_delete( &list, 0, 0 );
+        CHECK( node == &node2 );
+        CHECK( list.head == &node2 );
+        CHECK( list.tail == &node2 );
+    }
+
+    TEST(Verify_delete_deletes_element_1_of_a_list_of_length_3)
+    {
+        sll_node_t  node1 = { (void*)0x1234, NULL };
+        sll_node_t* node2 = sll_new_node((void*)0x1234);
+        sll_node_t  node3 = { (void*)0x1234, NULL };
+        node1.next = node2;
+        node2->next = &node3;
+        sll_t list = { &node1, &node3 };
+        sll_node_t* node = sll_delete( &list, 1, 0 );
+        CHECK( node == &node3 );
+        CHECK( node1.next == &node3 );
+        CHECK( list.head == &node1 );
+        CHECK( list.tail == &node3 );
+    }
+
+    TEST(Verify_delete_deletes_element_1_of_a_list_of_length_2)
+    {
+        sll_node_t  node1 = { (void*)0x1234, NULL };
+        sll_node_t* node2 = sll_new_node((void*)0x1234);
+        node1.next = node2;
+        sll_t list = { &node1, node2 };
+        sll_node_t* node = sll_delete( &list, 1, 0 );
+        CHECK( node == NULL );
+        CHECK( list.head == &node1 );
+        CHECK( list.tail == &node1 );
     }
 }