CPSC 321:501-503 - Computer Architecture
Texas A&M University
Department of Computer Science
Fall 2006
Lab 4 (100 pts) – Towers of Hanoi
Complete by yourself
Release date: 25 September 2006
Due date: One week after the lab
1. Towers of Hanoi problem
Facts (from www.lawrencehallofscience.org):
The Tower of Hanoi (sometimes referred to as the Tower of Brahma or the End of the World Puzzle)
was invented by the French mathematician, Edouard Lucas, in 1883. He was inspired by a legend that
tells of a Hindu temple where the pyramid puzzle might have been used for the mental discipline of
young priests. Legend says that at the beginning of time the priests in the temple were given a stack of
64 gold disks, each one a little smaller than the one beneath it. Their assignment was to transfer the 64
disks from one of the three poles to another, with one important provision; a large disk could never be
placed on top of a smaller one. The priests worked very efficiently, day and night. When they finished
their work, the myth said, the temple would crumble into dust and the world would vanish.
The objective of this assignment is to write a MIPS assembly program to solve the Towers of Hanoi
problem and to demonstrate the steps from the initial to the final configuration. Accept as input, the
number of disks (N) to be moved (Assume the number will be <=32).
Problem formulation
There are N disks labeled 1..N, with the larger label indicating a larger disk. These disks can be stacked
on poles A, B and C. Initially all disks form a tower on pole A, as shown.
1 1
2 2
. .
. .
. .
N N
----- ----- ----- ----- ----- -----
A B C A B C
Initial state Final state
The problem is to move the tower from A to C with the help of tower B, according to the following
rules:
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CPSC 321
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Lab 4
9/1/2006
file://H:\web_courses\cpsc321\labs\lab4_06c.html
