csce420pine64backup/hw1/420hw1-17fall.txt

(Print this page as a cover sheet for your printouts)

CSCE 420 HOMEWORK 1 (UPDATED)
Dr. Daugherity
Section: ______________ 
Due: 11:59 P.M. Monday, October 2, 2017

"On my honor, as an Aggie, I have neither given nor received any unauthorized 
aid on any portion of the academic work included in this assignment."


________________________________	________________________________
Typed or printed name of student	           Signature of student

NOTE:  Please follow your lab instructor's directions for submitting your 
assignment through CSNET.  ONLY ASSIGNMENTS SUBMITTED TO CSNET WILL BE GRADED!
Make a printout of each source file and staple it behind this cover sheet.
Sign it and turn it in in class Tuesday.  IF YOU DO NOT TURN IN A SIGNED COVER 
SHEET YOUR WORK WILL NOT BE GRADED!

NOTE:  Homework will be graded on build.tamu.edu, using g++ 7.2.0 with 
-std=c++17, or javac and java, or python3.6 (not python or python2 or python3).

You are free to develop your programs on any other platform, but it is your 
responsibility to make sure your programs also compile and execute correctly on
build.tamu.edu as specified.

NOTE:  Each file submitted (hw1pr1.cpp, etc.--see below) must begin as follows:
//Your name and UIN
//CSCE 420
//Due: Ocotber 2, 2017
//hw1pr1.cpp (or whatever this file name is)

NOTE:  Also write a README.txt file with whatever information is needed to
compile and run your programs.  Zip the README.txt and the homework files into
a single file named hw1.zip and submit to CSNET.

The grade for this lab will be based on style (formatting, variable names, 
comments, etc.), syntax (no compilation or link errors), and correctness 
(passes all test cases).  Your grade for this lab is:
Problem #	 1       2       3       4 
Style             /2      /4      /4      /2 
Syntax            /3      /6      /6      /3 
Correctness       /5      /10     /10     /5
-------------------------------------------------------------------
Total             /10     /20     /20     /10
Grand total _____/50

1. (10 points) Given a file containing a list of points (x,y) in the plane, 
write a greedy best-first search to find a closed path connecting all the 
points (the "Travelling Salesperson Problem") and output its length.  You may 
assume that x and y are non-negative integers that will fit in a 32-bit int.  
Each line of input will be the x and y coordinates for a point; keep reading 
until EOF.  You may assume there will be no more than 10000 points and that
the input file will be named hw1pr1_data.txt.

For example, if the input file contains
0 0
0 1
1 1
1 2

the output to the screen is (probably) 
0 0
0 1
1 1
1 2
5.236

The run time should be 60 seconds or less for up to 10000 points.  Hint: use 
the UNIX timeout command to automatically stop execution after 60 seconds.  
Name your program hw1pr1.cpp or Hw1Pr1.java or hw1pr1.py.

2. (20 points) The shortest closed path for the example points in problem 1 is
actually 4.828.  In other words, greeedy best-first search did not find the
shortest path.  Modify your program for problem 1 to do an iterative deepening 
search to the depth of the number of points, with the path cost the total 
distance.  To keep the search space manageable only include the 4 nearest 
unvisited points as successors when you expand a node.

The run time should be 60 seconds or less for up to 10000 points.  Hint: use 
the UNIX timeout command to automatically stop execution after 60 seconds.  
Name your program hw1pr2.cpp or Hw1Pr2.java or hw1pr2.py.

3. (20 points)  Write a breadth-first search program to solve 15-puzzle problems
in the same way as the 8-puzzle in Figure 3.4 on page 71.  Keep track of the 
number of nodes expanded and print that out along with the steps to solve the 
problem.  Define the legal moves as "swap the blank with an adjacent tile,"
resulting in the blank's moving up, down, left, or right.  A sample run should 
look like this:

	Enter 15-puzzle starting state by rows (0 for blank):
	1,2,3,4,5,6,7,8,9,10,0,11,13,14,15,12
	Enter ending state by rows (0 for blank): 
	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0
	Solution: 
		Start	 1  2  3  4
			 5  6  7  8
			 9 10  0 11
			13 14 15 12
	Swap the blank
		Right	 1  2  3  4
			 5  6  7  8
			 9 10 11  0
			13 14 15 12
			
		Down	 1  2  3  4
			 5  6  7  8
			 9 10 11 12
			13 14 15  0

	Done!  Generated xx states.

Note: To keep the time and memory requirements reasonable, your program only 
needs to solve 15-puzzle problems which have a solution in 10 moves or less.
Name your program Hw1Pr3.java or hw1pr3.cpp or hw1pr3.py.

OPTIONAL EXTRA CREDIT 
=====================
4. (10 points)  Modify problem 3 to use A* or IDA* search with Manhattan
distance for h; e.g., the starting state on page 103 has a Manhattan distance 
of 18 from the goal state (the sum of the number of rows and columns each tile 
must move from its starting position to its ending position).  You should see 
a marked reduction in the number of states generated, especially for problems 
which require more moves.  Here is a puzzle which requires 80 moves:

	Enter 15-puzzle starting state by rows (0 for blank):
	0,12,11,13,15,14,10,9,3,7,6,2,4,8,5,1
	Enter ending state by rows (0 for blank): 
	1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,0

Your program should solve it in 60 seconds or less.  Name your program 
Hw1Pr4.java or hw1pr4.cpp or hw1pr4.py.