Is {@code i} an index on this priority queue? @param i an index @return {@code true} if {@code i} is an index on this priority queue; {@code false} o

Provide a number which is not assigned to anyone. @return - Return an available number. Return -1 if none is available.

Draws one pixel at (<em>x</em>, <em>y</em>). This method is private because pixels depend on the display. To achieve the same effect, set the pen radi

Set the pen color to the default color (black).

Moves the snake. @param direction - 'U' = Up, 'L' = Left, 'R' = Right, 'D' = Down @return The game's score after the move. Return -1 if game

Returns true if the message should be printed in the given timestamp, otherwise returns false. If this method returns false, the message will not

Clears the screen to the default color (white).

Go to bottom of the tree by left side. So right side can be smaller. @param node @return

Draws a line segment between (<em>x</em>₀, <em>y</em>₀) and (<em>x</em>₁, <em>y</em>₁). @param x0 the <e

Pause for t milliseconds. This method is intended to support computer animations. @param t number of milliseconds

Sets the font to the default font (sans serif, 16 point).

Copies the offscreen buffer to the onscreen buffer, pauses for t milliseconds and enables double buffering. @param t number of milliseconds @deprecate

Returns the number of keys on this priority queue. @return the number of keys on this priority queue

Heap helper functions.