Project Three: Simple World

Description

I. Motivation

1. To give you experience in using arrays, pointers, structs, enums, and different I/O streams and writing program that takes arguments.

2. To let you have fun with an application that is extremely captivating.

II. Introduction

The simple world program we will write for this project simulates a number of creatures running around in a simple square world. The world is an m-by-n two-dimensional grid of squares (The number m represents the height of the grid and the number n represents the width of the grid.). Each creature lives in one of the squares, faces in one of the major compass directions (north, east, south, or west) and belongs to a particular species, which determines how that creature behaves.

fl

la

ho

ho	fl

Figure 1. A 4-by-4 grid, which contains five creatures. Two creatures belong to the species flytrap (whose short name is “fl”), two belong to the species hop (whose short name is “ho”), and one belongs to the species landmine (whose short name is “la”). The direction of each creature is represented by the direction of the arrow.

represented by the direction of the arrow. For example, the flytrap at the top row is facing east and the flytrap at the bottom row is facing west.

Table 1. The list of instructions and their explanations.

			The creature moves forward as long as the square it is facing is empty. If
hop			moving forward would put the creature outside the boundaries of the grid or
			would cause it to land on top of another creature, the hop instruction does
			nothing.
left			The creature turns left 90 degrees to face in a new direction.
right			The creature turns right 90 degrees to face in a new direction.
			If the square immediately in front of this creature is occupied by a creature of
			a different species (an “enemy”), that enemy creature is infected to become
			the same as the infecting species. When a creature is infected, it keeps its
infect			position and orientation, but changes its internal species indicator and begins
			executing the same program as the infecting creature, starting at step 1. If the
			square immediately in front of this creature is empty, outside the grid, or
			occupied by a creature of the same species, the infect instruction does
			nothing.
			If the square in front of the creature is inside the grid boundary and
ifempty		n	unoccupied, jump to step n of the program; otherwise, go on with the next
			instruction in sequence.
			If the creature is facing the border of the grid (which we imagine as
ifwall	n		consisting of a huge wall) jump to step n of the program; otherwise, go on
			with the next instruction in sequence.
ifsame	n		If the square the creature is facing is occupied by a creature of the same
			species, jump to step n; otherwise, go on with the next instruction.
ifenemy		n	If the square the creature is facing is occupied by a creature of an enemy
			species, jump to step n; otherwise, go on with the next instruction.
go n			This instruction always jumps to step n, independent of any condition.

Each species has an associated program which controls how each creature of that species behaves. Programs are composed of a sequence of instructions. The instructions that can be part of a program are listed in Table 1. There are nine legal instructions in total. The last five instructions have an additional integer argument.

Program is an attribute associated with species. Creatures of the same species have the same program. However, different species have different programs.

For example, the program of the species flytrap is composed of the following five instructions:

ifenemy 4

left

go 1

infect

go 1

The meaning of each instruction for this example is commented below:

(step 1) ifenemy 4 # If there is an enemy ahead, go to step 4

(step 2)		left		# Turn left
(step 3)		go	1	# Go to	step	1
(step	4)	infect		# Infect the		adjacent creature
(step	5)	go	1	# Go to	step	1

We will simulate the behaviors of all the creatures for a user specified number of rounds. In each round, creatures take their turns one by one, starting from the first creature. After the first creature finishes its turn, the second creature begins its turn. So on and so forth. One round ends with the last creature finishing its turn. Then the next round begins with the first creature taking its turn. Note that during the simulation, a creature may infect another creature so that the infected one changes its species. However, the simulation order of the infected creature does not change.

Each creature also maintains a variable called program counter which stores the index of the instruction it is going to execute. On each turn of a creature, it executes a number of instructions of its program, starting from the step indicated by the program counter. A program ordinarily continues with each new instruction in sequence, although this order can be changed by certain instructions in the program such as the if*** instructions. In each turn, a creature can execute any number of if*** or go instructions without relinquishing this turn. Its turn ends only when the creature executes one of the instructions: hop, left, right, or infect. After its turn ends, the creature updates the program counter to point to the next instruction, which will be executed at the beginning of its next turn.

Note that each creature maintains its own program counter, so that two different creatures belonging to the same species can have different program counters. The indices of the

instructions start from one, i.e., the first instruction of each program is “step 1”. At the very beginning of the simulation process, the program counters of all the creatures are set to their first instructions.

III. Available Types

In completing this project, you will have the following types available to you. They are defined in the file world_type.h.

const unsigned int MAXSPECIES = 10; // Max number of species in the // world

const unsigned int MAXPROGRAM = 40; // Max size of a species program const unsigned int MAXCREATURES = 50; // Max number of creatures in

// the world

const unsigned int MAXHEIGHT = 20; // Max height of the grid const unsigned int MAXWIDTH = 20; // Max width of the grid

struct point_t

{

int r;

int c;

};

/*

• Type: point_t

• ————

• This type is used to represent a point in the grid.

• Its component r corresponds to the row number; its component

• c corresponds to the column number.

*/

enum direction_t { EAST, SOUTH, WEST, NORTH }; /*

• Type: direction_t

• —————-

• This type is used to represent direction, which can take on

• one of the four values: East, South, West, and North.

*/

const string directName[] = {“east”, “south”, “west”, “north”}; // An array of strings representing the direction name.

const string directShortName[] = {“e”, “s”, “w”, “n”};

• An array of strings representing the short names for directions. enum opcode_t {HOP, LEFT, RIGHT, INFECT, IFEMPTY, IFENEMY,

IFSAME, IFWALL, GO};

/*

• Type: opcode_t

• ————-

• The type opcode_t is an enumeration of all of the legal

• command names.

*/

const string opName[] = {“hop”, “left”, “right”, “infect”, “ifempty”, “ifenemy”, “ifsame”, “ifwall”, “go”};

// An array of strings representing the command name.

struct instruction_t

{

opcode_t op;

unsigned int address;

};

/*

• Type: instruction_t

• ——————

• The type instruction_t is used to represent an instruction

• and consists of a pair of an operation code and an integer.

• For some operation code, the integer stores the address of

• the instruction it jumps to. The address is optional.

*/

struct species_t

{

string name;

unsigned int programSize;

instruction_t program[MAXPROGRAM];

};

/*

• Type: species_t

• ——————

• The type species_t is used to represent a species

• and consists of a string, an unsigned int, and an array

• of instruction_t. The string gives the name of the

• species. The unsigned int gives the number of instructions

• in the program of the species. The array stores all the

• instructions in the program according to their sequence.

*/

struct creature_t

{

point_t location;

direction_t direction;

species_t *species;

unsigned int programID;

};

/*

• Type: creature_t

• ——————

• The type creature_t is used to represent a creature.

• It consists of a point_t, a direction_t, a pointer to

• species_t and an unsigned int. The point_t gives the location of

• the species. The direction_t gives the direction of the species.

• The pointer to species_t points to the species the creature belongs

• to. The programID gives the index of the instruction to be

• executed in the instruction_t array of the species.

*/

struct grid_t

{

unsigned int height;

unsigned int width;

creature_t *squares[MAXHEIGHT][MAXWIDTH];

};

/*

• Type: grid_t

• ——————

• The type grid_t consists of the height and the width of the grid

• and a two-dimensional array of pointers to creature_t. If there is

• a creature at the point (r, c) in the grid, then squares[r][c]

• stores a pointer to that creature. If point (r, c) is not occupied

• by any creature, then squares[r][c] is a NULL pointer.

*/

struct world_t

{

unsigned int numSpecies;

species_t species[MAXSPECIES];

unsigned int numCreatures;

creature_t creatures[MAXCREATURES];

grid_t grid;

};

/*

• Type: world_t

• ————–

• This type consists of two unsigned ints, an array of species_t,

• an array of creature_t, and a grid_t object. The first unsigned

• int numSpecies specifies the number of species in the creature

• world. The second unsigned int numCreatures specifies the number

• of creatures in the world. All the species are stored in the array

• species and all the creatures are stored in the array creatures.

• The grid is given in the object grid.

*/

IV. File Input

All the species, the programs for all the species, and the initial layout of the creature world are stored in files and these files will be read by your program to set up the simulation environment. Note: when you read files, you must use input file stream ifstream. Otherwise, since the files are read-only on our online judge, you may fail to read the files.

As we described before, each species has an associated program. The program for each species is stored in a separate file whose name is just the name of that species. For example, the program for the species flytrap is stored in a file called flytrap.

A file describing a program contains all the instructions of that program in order. Each line lists just one instruction. The first line lists the first instruction; the second line lists the second instruction; so on and so forth. Each instruction is one of the nine legal instructions described in Table 1. The program ends with the end of file or a blank line. Comments may appear after the blank line or at the end of each instruction line. For example, the program file for the flytrap species looks like:

ifenemy 4 If there is an enemy, go to step 4.

left If no enemy, turn left.

go 1

infect

go 1

The flytrap sits in one place and spins.

It infects anything which comes in front.

Flytraps do well when they clump.

Note that in writing functions for reading these program files, you should handle the comments correctly, which means that you should ignore these comments when setting up the program for a species.

Since there are many species, we stored all of their program files in a directory.

To help you get all the species and their program files, we also have a file telling the directory where the program files are stored and listing all the species. We call this file a species summary. The first line of this file shows the directory where all of the program files are stored. The next

lines list all the species, with one species per line. For example, the following is a species summary file:

creatures

flytrap

hop

landmine

From this file, we can learn that the program files are stored in the directory called creatures. We have three species to simulate, which are flytrap, hop, and landmine. By first reading the species summary file, you will know where to find the program file for each species.

Finally, there is a file describing the initial state of the creature world. We call it a world file. The first line of this file gives the height of the two-dimensional grid (i.e., the number of rows) and the second line gives the width of the grid (i.e., the number of columns). The remaining lines of this file describe all the creatures to simulate and their initial directions and locations, with one creature per line. Each of these lines has the following format:

<species> <initial-direction> <initial-row> <initial-column>

where <species> is one of the species from the species summary file, <initial-direction> describes the initial direction and is one of the strings “east”, “south”, “west”, and “north”. <initial-row> describes the initial row location of the

creature. We use the convention that the top-most row of the grid is row 0 and the row number increases from top to bottom. <initial-column> describes the initial column

location of the creature. We use the convention that the left-most column of the grid is column 0 and the column number increases from left to right. An example of a world file looks like:

4

4

hop east 2 0

flytrap east 2 2

It says that the size of the grid is 4-by-4 and there are two creatures in the world. The first creature belongs to the species hop. It faces east and lives at point (2, 0) initially. The second creature belongs to the species flytrap. It faces east and lives at point (2, 2) initially.

In the simulation, the order on the creatures to simulate is important. This order is determined by the order that these creatures appear in the world file.

V. Program Arguments

Your program will obtain the names of the species summary file and the world file via program arguments. Additionally, your program will be told the number of rounds to simulate and whether it should print the simulation result verbosely or not.

The expected order of arguments is:

<species-summary> <world-file> <rounds> [v|verbose]

The first three arguments are mandatory. They give the name of the species summary file, the name of the world file, and the number of simulation rounds, respectively. The last argument is optional. If the last argument is the string “v” or the string “verbose”, your program should print the simulation result verbosely, which will be explained later. Otherwise, if it is omitted or is any other string, your program should print the result concisely, which will also be explained later.

Suppose that you program is called p3. It may be invoked by typing in a terminal:

./p3 species world 10 v

Then your program should read the species summary from the file called “species” and the world file from the file called “world”. The number of simulation rounds is 10. Your program should print the simulation information verbosely.

VI. Error Checking and Error Message

Your program should check for errors before it starts to simulate the moves of the creatures. If any error happens, your program should issue an error message and then exit. If there are no errors happening, then the initial state of the creature world is legal and your program can start simulating the creature world.

We require you to do the following error checking and print the error message in exactly the same way as described below. Note that some of the output error message has two lines and each error message should be ended with a newline character. All error messages should be sent to the standard output stream cout; none to the standard error stream cerr.

1. Check whether the number of arguments is less than three. If it is less than three, then one of the mandatory arguments is missing. You should print the following error message:

Error: Missing arguments!

Usage: ./p3 <species-summary> <world-file> <rounds> [v|verbose]

2. Check whether the value <rounds> supplied by the user is negative. If it is negative, you should print the following error message:

Error: Number of simulation rounds is negative!

3. Check whether file open is successful. If opening species summary file, world file, or any species program file fails (for example, the file to be opened does not exist), print the following error message:

Error: Cannot open file <filename>!

where <filename> should be replaced with the name of the file that fails to be opened. If that file is not in the same directory as your program, you need to include its path in the <filename>. As you may know, there are multiple ways to specify a path. For us, the path name should be specified in the most basic way, i.e., “<dir>/<filename>” (not “./<dir>/<filename>”, “<dir>//filename”, etc.). Once you find a file that cannot be opened, issue the above error message and terminate your program.

4. Check whether the number of species listed in the species summary file exceeds the maximal number of species MAXSPECIES. If so, print the following error message:

Error: Too many species!

Maximal number of species is <MAXSPECIES>.

where <MAXSPECIES> should be replaced with the maximal number of species set by your program.

5. Check whether the number of instructions for a species exceeds the maximal size of a species program MAXPROGRAM. If so, print the following error message:

Error: Too many instructions for species <SPECIES_NAME>! Maximal number of instructions is <MAXPROGRAM>.

where <SPECIES_NAME> should be replaced with the name of the species whose program has more instructions than the maximal number allowed and <MAXPROGRAM> should be replaced with the maximal size of a species program set by your program.

6. Check whether the species program file contains illegal instructions. We only allow nine instructions as listed in Table 1. Your program needs to check whether the instruction name is one of the nine legal instruction names listed in the string array opName (which is defined in Section III). If an instruction name is not recognized, you should print the following error message:

Error: Instruction <UNKNOWN_INSTRUCTION> is not recognized!

where <UNKNOWN_INSTRUCTION> should be replaced with the name of the unrecognized instruction. You can assume that for any recognized instruction, it is given in the correct format. Thus, you don’t need to check whether an integer is appended after the instruction name or not. If there are multiple unrecognized instruction names, you only need to print out the first one and then terminate the program.

7. Check whether the number of creatures listed in the world file exceeds the maximal number of creatures MAXCREATURES. If so, print the following error message:

Error: Too many creatures!

Maximal number of creatures is <MAXCREATURES>.

where <MAXCREATURES> should be replaced with the maximal number of creatures allowed by your program.

8. Check whether each creature in the world file belongs to one of the species listed in the species summary file. If the species for a creature is not recognized, print the following error message:

Error: Species <UNKNOWN_SPECIES> not found!

where <UNKNOWN_SPECIES> should be replaced with the unrecognized species. If there are multiple unrecognized species, you only need to print out the first one and then terminate the program.

9. Check whether the direction string for each creature in the world file is one of the strings in the array directName (which is defined in Section III). If the direction string is not recognized, print the following error message:

Error: Direction <UNKNOWN_DIRECTION> is not recognized!

where <UNKNOWN_DIRECTION> should be replaced with the unrecognized direction name. If there are multiple unrecognized direction names, you only need to print out the first one and then terminate the program.

10. Check whether the grid height given by the world file is legal. A legal grid height is at least ONE and less than or equal to a maximal value MAXHEIGHT. If the grid height is illegal, print the following error message:

Error: The grid height is illegal!

11. Check whether the grid width given by the world file is legal. A legal grid width is at least ONE and less than or equal to a maximal value MAXWIDTH. If the grid width is illegal, print the following error message:

Error: The grid width is illegal!

12. Check whether each creature is inside the boundary of the grid. If any creature is outside the boundary, print the following error message:

Error: Creature (<SPECIES> <DIR> <R> <C>) is out of bound! The grid size is <HEIGHT>-by-<WIDTH>.

where <SPECIES> should be replaced with the species the creature belongs to, <DIR> be replaced with the direction the creature is facing, <R> be replaced with the row location of the creature, <C> be replaced with the column location of the creature, <HEIGHT> be replaced with the height of the grid, and <WIDTH> be replaced with the width of the grid. Here, we use the four-tuple (<SPECIES> <DIR> <R> <C>) to identify the creature. For example, if given the following world file:

3

3

flytrap east 0 0

hop south 3 2

food west 2 1

then Creature (hop south 3 2) is outside the boundary. Then, the error message should be:

Error: Creature (hop south 3 2) is out of bound!

The grid size is 3-by-3.

If there are multiple creatures outside the boundary, you only need to print out the first one and then terminate the program.

13. Check whether each square in the grid is occupied by at most one creature. If any square is occupied by more than one creature, print the following error message:

Error: Creature (<SP1> <DIR1> <R> <C>) overlaps with creature (<SP2> <DIR2> <R> <C>)!

where (<R> <C>) identifies the square which is occupied by more than one creature, the first four-tuple (<SP1> <DIR1> <R> <C>) identifies the second creature in order that occupies the square, and the second four-tuple (<SP2> <DIR2> <R> <C>) identifies the first creature in order that occupies the square. Once you find two creatures occupying the same square, you issue the above error message and then terminate the program.

Since you may implement the error checking in different order and in the case that there is more than one error, the first error message printed out may be different. Therefore, we will only test your error checking using test cases containing just one error.

VII. Simulation Output

Once all of the above error checkings on the initial state of the creature world are passed, you can start simulating the creature world. You should print to the standard output the simulation information, either in a verbose mode or in a concise mode, depending on whether an additional argument “v” or “verbose” is provided by the user.

In the verbose mode, you first print the initial state of the world. In doing so, you begin with printing the string “Initial state” followed by a newline. Then you graphically show the layout of the initial grid using just characters. Each square takes a four-character field in your terminal. Adjacent squares on the same row are separated by one space. If a square in the grid is not occupied by any creature, the field for that square is filled with FOUR “_”. If a square is occupied by a creature, then the first two characters of the field for that square are the first two letters of the name of the species the creature belongs to. (We assume that all the species names contain at least two characters and no two species names have the identical first two characters.) The third character in the field is a “_” and the fourth character is the first character of the direction the creature faces, i.e., “e” for “east”, “s” for “south”, “w” for “west”, and “n” for “north”.

For example, suppose a world file looks like

4

4

hop east 2 0

flytrap east 2 2

Then the layout of the initial grid is printed as

____ ____ ____ ____

____ ____ ____ ____

ho_e ____ fl_e ____

____ ____ ____ ____

Note that there is a space at the end of each line.

After printing the initial layout, we begin the simulation from the first round to the last round specified by the user. In the i-th simulation round, you first print “Round <i>” followed by the newline. For example, in the first round, you should first print

Round 1

During each simulation round, you simulate the moves of all the creatures in turn. When starting simulating a creature, you announce that this creature takes action by printing

Creature (<SPECIES> <DIR> <R> <C>) takes action:

followed by a newline. In the above output, the four-tuple (<SPECIES> <DIR> <R> <C>) shows the state of the creature right before it takes the action, where <SPECIES> should be replaced with the species the creature belongs to, <DIR> be replaced with the direction the creature is facing, <R> be replaced with the row location of the creature, and <C> be replaced with the column location of the creature.

After this, you print the sequence of instructions that the creature executes for its turn. This sequence may include any number of if*** and go instructions and end with one of the hop, left, right, and infect instruction. You should print the sequence of instructions the creature executes in order, with one instruction per line. The output format for an instruction is:

Instruction <INSTR_NO>: <INSTR_NAME> [GOTO_STEP]

where <INSTR_NO> should be replaced with the number of that instruction in the program (the number starts from 1), <INSTR_NAME> should be replaced with the name of the instruction, and [GOTO_STEP] is the number in an if*** or a go instruction and is optional.

After printing the last instruction of the creature under consideration, you should print the updated layout of the grid, using the same rule as you print the initial layout.

Now let’s look at an example. Suppose that the program for the species hop is

hop

go 1

and the program for the species flytrap is

ifenemy 4		If there is an enemy, go to step 4.
left		If no enemy, turn left.
go	1
infect
go	1

Then, given the following world file

4

4

hop east 2 0

flytrap east 2 2

the simulation information for the first round is printed as

Round 1

Creature (hop east 2 0) takes action:

Instruction 1: hop

____ ____ ____ ____

____ ____ ____ ____

____ ho_e fl_e ____

____ ____ ____ ____

Creature (flytrap east 2 2) takes action:

Instruction 1: ifenemy 4

Instruction 2: left

____ ____ ____ ____

____ ____ ____ ____

____ ho_e fl_n ____

____ ____ ____ ____

The simulation information for the second round is printed as

Round 2

Creature (hop east 2 1) takes action:

Instruction 2: go 1

Instruction 1: hop

____ ____ ____ ____

____ ____ ____ ____

____ ho_e fl_n ____

____ ____ ____ ____

Creature (flytrap north 2 2) takes action:

Instruction 3: go 1

Instruction 1: ifenemy 4

Instruction 2: left

____ ____ ____ ____

____ ____ ____ ____

____ ho_e fl_w ____

____ ____ ____ ____

In the concise mode, you print the initial state of the world in the same way as in the verbose mode. When printing the simulation information for the i-th round, you first print “Round <i>” followed by the newline. Then you print the final action of each creature in turn, with one creature per line. The format is:

Creature (<SPECIES> <DIR> <R> <C>) takes action: <LAST_INSTR>

Same as in the verbose mode, the four-tuple (<SPECIES> <DIR> <R> <C>) shows the state of the creature right before it takes the action. <LAST_INSTR> should be replaced with the last instruction the creature executes for its turn, which is one of the hop, left, right, and infect instruction.

After printing the final actions for all the creatures, you print the updated layout at the end of this round.

For the same world file as above:

4

4

hop east 2 0

flytrap east 2 2

In the concise mode, the simulation information for the first round is printed as

Round 1

Creature (hop east 2 0) takes action: hop

Creature (flytrap east 2 2) takes action: left

____ ____ ____ ____

____ ____ ____ ____

____ ho_e fl_n ____

____ ____ ____ ____

The simulation information for the second round is printed as

Round 2

Creature (hop east 2 1) takes action: hop

Creature (flytrap north 2 2) takes action: left

____ ____ ____ ____

____ ____ ____ ____

____ ho_e fl_w ____

____ ____ ____ ____

There are no blank lines in the output for both the verbose and concise mode.

VIII. Source Code Files and Compiling

There is a source code file located in the Project-3-Related-Files.zip from our

Canvas Resources:

world_type.h: The header file which defines a number of types for you to use.

You should copy this file into your working directory. DO NOT modify it!

You need to write three other source code files. The first file is named as simulation.h, which contains the declarations for all the functions you write, just like the p2.h in our project two. The second file is named as simulation.cpp, which contains all the implementations of those functions declared in the simulation.h. The third file is named as p3.cpp, which contains only the main function. After you have written these files, you can type the following command in the terminal to compile the program:

g++ -Wall -o p3 p3.cpp simulation.cpp

This will generate a program called p3 in your working directory. In order to ensure that the online judge compiles your program successfully, you should name you source code files exactly like how they are specified above.

IX. Implementation Requirements and Restrictions

1. In writing your code, you may use the following standard header files: <iostream>,

<fstream>, <sstream>, <iomanip>, <string>, <cstdlib>, and <cassert>. No other header files can be included.

2. You may not define any global variables yourself. You can only use the global constant ints and string arrays defined in world_type.h.

3. Pass large structs by reference rather than value. Where appropriate, pass const references / pointers-to-const. Do not pass lots of little arguments when you can pass an appropriate, larger structure instead.

4. All required output should be sent to the standard output stream; none to the standard error stream.

5. You should strive not to duplicate identical or nearly‐identical code, and instead collect such code into a single function that can be called from various places. Each function should do a single job, though the definition of “job” is obviously open to interpretation. Most students write too few functions that are too large.

X. Hints and Tips

1. This project will take you longer than project two did, so start early!

2. Do this project in stages. First, be able to read the species summary file. Second, be able to read the programs for all the species. Third, be able to read the world file. Write some diagnostic code that can print out the species summary, the program for each species, and the creatures, to make sure that you are reading them correctly. Implement the error checking and test it with different illegal inputs. Once you can read the structures in, implement the simple moves such as left and right. Once you have that working, implement moves such as hop and infect. Finally, implement if*** and go instructions.

3. Take advantage of the fact that enumerations are sequentially numbered from 0 to N‐1.

4. Use the right methods of input file stream to read file. In some cases, you may first use the getline() function to read the entire line of a file and then use an input string stream to extract the content from that line.

5. The hop instruction will only cause the creature to move forward when the square it is facing is empty. If moving forward would put the creature outside the boundaries of the grid or would cause it to land on top of another creature, the hop instruction does nothing. However, although the hop action is not executed successfully, you should update the program counter so that it points to the next instruction after this hop instruction. The similar situation also applies to the infect instruction. If there is no enemy to infect, the infect operation does nothing. However, you should update the program counter to its next instruction.

6. As a hint, you probably need to write the following eight functions or some variations of them. However, these are not the only functions you have to write. You probably need to write more functions for different jobs.

bool initWorld(world_t &world, const string &speciesFile, const string &creaturesFile);

• MODIFIES: world

• EFFECTS: Initialize “world” given the species summary file

• “speciesFile” and the world description file

• “creaturesFile”. This initializes all the components of

• “world”. Returns true if initialization is successful.

void simulateCreature(creature_t &creature, grid_t &grid, bool verbose);

• REQUIRES: creature is inside the grid.

• MODIFIES: creature, grid, cout.

//

• EFFECTS: Simulate one turn of “creature” and update the creature,

• the infected creature, and the grid if necessary.

• The creature programID is always updated. The function

• also prints to the stdout the procedure. If verbose is

• true, it prints more information.

void printGrid(const grid_t &grid);

• MODIFIES: cout.

• EFFECTS: print a grid representation of the creature world.

point_t adjacentPoint(point_t pt, direction_t dir);

• EFFECTS: Returns a point that results from moving one square

• in the direction “dir” from the point “pt”.

direction_t leftFrom(direction_t dir);

• EFFECTS: Returns the direction that results from turning

• left from the given direction “dir”.

direction_t rightFrom(direction_t dir);

• EFFECTS: Returns the direction that results from turning

• right from the given direction “dir”.

instruction_t getInstruction(const creature_t &creature); // EFFECTS: Returns the current instruction of “creature”.

creature_t *getCreature(const grid_t &grid, point_t location); // REQUIRES: location is inside the grid.

//

// EFFECTS: Returns a pointer to the creature at “location” in “grid”.

XI. Testing

We provide you with a few test cases in the directory called tests, which can be found inside Project-3-Related-Files.zip from our Canvas Resources.

Inside the tests directory, there is an example species summary file called species and two subdirectories called creatures and world-tests. The creatures directory contains a number of species program files. The world-tests directory contains five world files and the files recording the correct outputs.

The first world file is called outside-world, which describes an illegal world with one creature located outside the boundary of the grid.

To run this test case, type the following commands:

./p3 species world-tests/outside-world 5 > outside-world.out

Then the output of your program is redirected to a file named outside-world.out. The correct output is recorded in the file outside-world.answer in the directory world-tests. You can use the diff command to check whether the file outside-world.out is same as the file outside-world.answer.

The second world file is called overlap-world, which describes an illegal world with two creatures located at the same square in the grid. You can run this test case using a similar command as shown above and compare your output with the correct output recorded in the file overlap-world.answer.

The next three world files world1, world2, and world3 are legal world files. You can run these test cases in the similar way. The number of simulation rounds for world1, world2, and world3 are 5, 20, and 40, respectively. For these test cases, we provide you with both the verbose and the concise output files. The verbose output files are these files named as *-verbose.answer and the concise output files are these files named as

*-concise.answer.

These are the minimal amount of tests you should run to check your program. Those programs that do not pass these tests are not likely to receive much credit. You should also write other different test cases yourself to test your program extensively. In doing so, you need to write your own legal/illegal species summary files, legal/illegal world files, and species program files. Indeed, it will be very interesting to create new species yourself and observe what kind of species will finally dominate the SIMPLE WORLD given different initial layout!

XII. Submitting and Due Date

You should submit your source code files simulation.h, simulation.cpp, and p3.cpp. These files should be submitted via the online judgment system. See announcement from the TAs for details about submission. The due date is 11:59 pm on July 2, 2019.

XIII. Grading

Your program will be graded along three criteria:

1. Functional Correctness

2. Implementation Constraints

3. General Style

Functional Correctness is determined by running a variety of test cases against your program, checking against our reference solution. We will grade Implementation Constraints to see if you have met all of the implementation requirements and restrictions. General Style refers to the ease with which TAs can read and understand your program, and the cleanliness and elegance of your code. For example, significant code duplication will lead to General Style deductions.