This is C code. I am trying to fill each node's Parent field with its parent because I am drawing nodes to the screen. However, I have not been able to get this working. Reading the output from the code and tracing it, it seems that the code does not continue recursing down into the tree to insert. Can someone please point me to what is wrong and help me understand why it is wrong? Thank you.
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struct AvlNode* Insert( gint X, struct AvlNode* T )
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{
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static struct AvlNode *Parent;
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static struct AvlNode *Root;
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static int level = 0;
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if(Parent && T != NULL)
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printf("\n\nThe Root is %d and the Parent is %d", T->Element, Parent->Element);
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if(T!= NULL)
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printf(" But T is %d \n", T->Element);
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if( T == NULL )
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{
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/* Create and return a one-node tree */
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T = g_malloc( sizeof( struct AvlNode ) );
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if( T == NULL )
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printf( "Error: Out of space!" );
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else
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{
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T->Element = X; T->Height = 0;
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T->Left = T->Right = NULL;
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//Special Case for Root Node
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if(FIRST_TIME)
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{
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T->rect_x = app.drawing_area->allocation.width/2 - 25;
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T->rect_y = 0;
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draw_node(T, app);
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Root = T;
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FIRST_TIME = 0;
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}
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}
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}
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else
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if( X < T->Element )
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{
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printf("\n%d is less than %d\n", X, T->Element);
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Parent = T;
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++level;
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T = Insert( X, T->Left );
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--level; //Finished Insert Call, decrement recursive level
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if(level == 0)
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T->Parent = Parent;
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//Draw T's Left Node to Screen
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LEFT_NODE = 1;
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T->rect_x = T->Parent->rect_x;
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T->rect_y = T->Parent->rect_y;
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draw_node(T, app);
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LEFT_NODE = 0;
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if( Height( T->Left ) - Height( T->Right ) == 2 )
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{
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printf("Performing Left Rebalancing\n");
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if( X < ( (T->Left)->Element ) )
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T = SingleRotateWithLeft( T );
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else
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T = DoubleRotateWithLeft( T );
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}
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}
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else
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if( X > T->Element )
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{
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printf("\n%d is greater than %d\n", X, T->Element);
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Parent = T;
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++level;
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T = Insert( X, T->Right );
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--level;
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if(level == 0)
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T->Parent = Parent;
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//Draw Right Node
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RIGHT_NODE = 1;
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T->rect_x = T->Parent->rect_x;
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T->rect_y = T->Parent->rect_y;
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//Draw T's Right Node to Screen
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draw_node(T, app);
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RIGHT_NODE = 0;
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if( Height( T->Right ) - Height( T->Left ) == 2 )
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{
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printf("Performing Right Rebalancing\n");
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if( X > ( (T->Right)->Element) )
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T = SingleRotateWithRight( T );
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else
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T = DoubleRotateWithRight( T );
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}
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}
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/* Else X is in the tree already; we'll do nothing */
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T->Height = Max( Height( T->Left ), Height( T->Right ) ) + 1;
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return T;
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}
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