(Simulation: self-avoiding random walk) A self-avoiding walk in a lattice is a path from...

(Simulation: self-avoiding random walk) A self-avoiding walk in a lattice is a path from one point to another which does not visit the same point twice. Self-avoiding walks have applications in physics, chemistry, and mathematics. They can be used to model chainlike entities such as solvents and polymers. Write a program that displays a random path that starts from the center and ends at a point on the boundary, as shown in Figure 16.28(a), or ends at a dead-end point (i.e., surrounded by four points that are already visited), as shown in Figure 16.28(b). Assume the size of the lattice is 16 by 16.