Write a program that simulates the following model for fire growth. We assume th

Question

Write a program that simulates the following model for fire growth. We assume that we have a rectangular grid with a fixed number of rows and columns. Initially, the grid is presumed to have trees that can fuel a fire. We then simulate a fire that starts at a specified cell off the grid. At each step, the fire burns out all of the fuel of its current cell, while moving to an adjacent cell that still has fuel (horizontally or vertically; not diagonally). In particular, if there is a choice of neighboring cells having fuel, it picks one of those choices uniformly at random for the next step. A trial should end when the fire either reaches a cell at the boundary of the grid, or when it reaches a location in which all neighboring squares have already been visited, in which case the fire bums out. Create a file fire, m implementing a function with the following specifications. function outcomes = fire (numRows, numCols, startRow, startcol,) % Simulate the spread of a fire. % USAGE: outcomes = fire (numRow, numcols, start Row, startcol.) % The simulation will be performed on a grid with % specified number of rows and columns, assumed to be numbered % starting at (1, 1) at the top-left, The fire begins at location % (StartRow, startcol) within that grid A series of frames from a trial of fire(7, 7, 4, 4) The next step goes to the left exiting the grid. The final frame of a trial fire(2e, se, 1e, 1s) in which the fire reaches the bottom edge of the region

Explanation / Answer

The pc doesn't visit the cabinet to get jellybeans and cups of direction, so this system makes use of numbers in preference to jellybeans, and variables in preference to cups. you can think about a variable as an area within the reminiscence of the computer that serves as a container for more than a few. let us take a look at this system line by line

int fredsCup; This line says: "make a variable so as to preserve an integer number, and make contact with the variable 'fredsCup'". This line, which asks for the variable to be made, is said to be a declaration of the variable. (surely, it in reality says "reserve an area in memory that is huge sufficient for an integer wide variety, and discuss with this location by means of the call 'fredsCup'". it's far simpler, I think, to imagine a variable to be like a container that has the call fredsCup, without disturbing about a few physical place inside the pc's memory.)

the line:

fredsCup = 5;

says "place the cost five into the variable fredsCup". this is your fundamental task statement, possibly the maximum vital announcement in programming. specific programming languages do it in a different way:

fredsCup <- five (APL)

fredsCup = 5; (C, C++, Java)

fredsCup := 5; (Pascal)

placed 5 into fredsCup (Hypertalk)

My non-public preferred of those is the APL style3; it is very clean you're putting five into fredsCup. My least favored is that of C or Java, because with out knowing the language you might assume that this declaration is making a declare that fredsCup is 5, which it would or may not be (for instance, "is fredsCup = five?), as an alternative of actually putting five into fredsCup. but, good day, we use

English, and i've already complained approximately one grammatical rule. we will stay with some annoyances in an otherwise cool language like Java

the line

myCup = fredsCup + katiesCup;

says "upload the contents of fredsCup to the contents of katiesCup and placed the result into myCup".

Output and Strings

the line

device.out.println("My cup has " + myCup); must be more or less self-explanatory, accurate? The only trouble might be the system.out.println business, which is a request to output a few textual content to the Java output window. inside the parentheses you placed some textual content, called a "String", and this String could be written into the output window.

Strings are unique gadgets that you will use plenty for input and output. you may concatenate Strings the usage of "+". as a result, "Num" + "ber" yields "range". So our little application entails no longer just numbers, however additionally Strings.

take into account that the String "64" is not similar to the range sixty four, any more than your signature, your picture and you're the same thing5. however, it turns out that you could write either "My fortunate quantity is " + "7" or "My fortunate variety is " + 7. within the former, Strings are concatenated; in the latter, it looks like a number of is being concatenated onto a String. In truth, when you try to do that, Java automatically converts the variety to its String representation before the concatenation6. that is what occurs inside the little software with "My cup has " + myCup. 7 What do you predict might be the text output by this system

word, by means of the way, that Java makes use of semicolons, no longer intervals, to cease its statements; this makes some feel, due to the fact you could think of them as being like complete ideas; in English, complete thoughts located in a single sentence are separated by using semicolons; you may think about the entire application as being just like the sentence; but, in Java, the program would not end in a length

Making the program run

It turns out the "program" I showed you might not certainly run just as proven above. to start with, in Java, you want to surround the code8 through a few stuff to get the program off the ground and running, as follows:

public elegance MyProgram

public static void important(String args[])

int fredsCup;

fredsCup = 5;

int katiesCup; katiesCup = 4;

int myCup;

myCup = fredsCup + katiesCup;

gadget.out.println("My cup has " + myCup);

we will provide an explanation for simply what all this means later. For now, you're going to make the program run.

unluckily, you can't really type the above application into a window and say "pc, run software" (honestly, you can nowadays, but not with the generation we have in our path). this system desires to be transformed into the shape so one can run in your laptop. in case you were to appearance interior a replica of Microsoft word, as an example, you wouldn't locate code that seems like Pascal or C or Java. you'd see usually gobbledygook, which can be very concise and simple instructions to the microprocesser for your pc. this is the "object code" or "machine language", which the computer can apprehend, rather than "supply code", written in Java or Pascal or C, which you may recognize. You want to use a unique software that interprets your source code into item code. This application is called a compiler. for the reason that item code a Macintosh can understand is

one-of-a-kind from that a windows system can recognize, you need to compile your supply code into extraordinary object code for Mac and windows. it is why you can't replica a program from a home windows machine and assume it to run on a Mac.

truly, what i have said doesn't pretty practice in the case of Java. A Java compiler does not pretty assemble the source code to item code for a Macintosh, or home windows pc, or any other specific form of laptop. instead, it compiles the source code to a unique kind of object code on the way to run on a Java virtual device. The Java virtual gadget is a application that runs on your computer. It pretends to be a unique Java pc (neither Mac nor windows nor...). Your compiled Java item code runs luckily on it, wondering that it's going for walks on a Java computer, while in fact it's simplest strolling on a digital machine (VM) program this is pretending to be a Java computer. each time the Java application feeds an training to the VM, the VM speedy translates the Java "item" code to the object code for the unique laptop the VM is running on (e.g., a Mac) which executes the instruction9. That manner the training absolutely receives accomplished to your laptop, and the VM efficiently keeps its ruse. Your genuine equal compiled Java code will run under a Java virtual system on a Mac, or on a computer, due to the fact these unique digital Machines gift the exact identical smiling Java VM face to the Java code, even supposing at the back of closed doorways the only VM interprets to Mac code and the alternative interprets to pc code.

So, one benefit of Java is that the exact identical application can be copied from one laptop to some other and run extra or less the equal. One disadvantage is that the Java VM is constantly translating instructions from Java byte code to the item code of the pc it's walking on. This constant translation slows down your software (it is precisely like speaking through an interpreter). Java packages run extra slowly than packages compiled with standard languages like C. In case this makes you depressed, (1) computers are awful fast nowadays, and (2) there are other benefits to Java that we can cope with later, which include the opportunity you may finish writing your program lots quicker. As a programmer, would you as an alternative store some time, or the laptop's time

Operators in the little instance application we have discussed, there are various factors at which manipulations or comparisons of numbers are made, and there is an implicit ensuing fee. The most apparent might be addition: fredsCup + katiesCup that is an expression, and its price is the sum of the contents of the 2 variables. The "+" image in this expression is an operator — it operates on the two numbers on either aspect of it to yield their sum as its result. It turns out there are different operators as well in the little program. The "+" image in the output is a String concatenation operator, as we've already seen. Even the "=" within the task assertion is considered an operator, however we may not worry about that now11. It probable does no longer marvel you that "+" is used for addition. consequently, myCup = fredsCup + katiesCup; says "add fredsCup to katiesCup and placed the bring about myCup". The symbols for subtraction, multiplication, and department are "-", "*", and "/", as follows: myCup = fredsCup - katiesCup; myCup = fredsCup * katiesCup; myCup = fredsCup / katiesCup;

Types

In our little example software, the variables had been indicated to be for holding integer numbers through the "int" in front in their names in which they first appear inside the application. Integer numbers are complete numbers, namely ... -three, -2, -1, zero, 1, 2, three, ... Java offers 4 exceptional forms of integer variables that you can use. those are byte, brief, int, and long. normally, we are able to use "int", but you must be aware about the differences. in case you declare a variable to be of kind "byte", it's going to take up simplest eight bits of space, that's fantastic in case you are area conscious, however it can take values best between -128 and +127. Variables of kind quick take in sixteen bits, int 32 bits, and lengthy sixty four bits, each with a respectively greater variety of integers that can be represented12. computer programs need to do extra than manipulate entire numbers, and so other fundamental sort of variable kinds are provided in Java. most glaringly, fractional or decimal numbers are needed. often known as actual or floatingpoint numbers in programming languages, those can be saved in Java in variables of types drift (32 bits) or double (sixty four bits). ultimately, variables of the boolean kind can take at the values real or fake

goals

on this chapter, you'll analyze philosophy and a way to move around in circles. we are able to cowl the primary subject matter of drift manipulate — how to manage what instruction this system executes subsequent. especially, you may learn how to application with: •if's and else's •loops of diverse types: for, whilst, do-even as.

waft manage

The little packages we have run to this point start with the primary line of instructions, then continue line by line to the lowest, like someone studying in English. you can think of the pc visiting thru this system line by using line, executing instructions. however, now and again a special coaching is encountered that tells the pc to leap to a specific vicinity inside the software, no longer necessarily the following line down. Such instructions (like switches on a train song) manipulate the drift of the program, and are important elements of programming.

If's and else's

regularly you may want to make a software's calculations depend on some condition, and an "if" declaration will do the job, as in: String response; if (n>1) reaction = "Plural"; else if (n==1) reaction = "Singular"; else response = "None"; With an "if" declaration, you can upload as many "else if"s as you need, to ask about all styles of alternative situations. you can have no "else if"s in case you want: if (n>3) reaction = "big"; else response = "Small"; or no else's: if (n0) response = "nice"; or only the if: if (n==0) reaction = "mistakes: n is 0"

word

the syntax: the situation to be tested is represented by means of an expression in parentheses.thirteen The expression inside parentheses have to take on a true or fake price (a boolean expression14).

Blocks

In each of the examples above, a unmarried statement takes place after the if, in any other case. What if you need to execute statements when the circumstance is true? Will the following work? if (n>3) reaction = "huge"; m = eight; else response = "Small"; the answer isn't any. Indentation is certainly best for human studying; it would not have any impact on how this system truely runs. The above is equivalent to: if (n>3) reaction = "big"; m = eight; else reaction = "Small"; as a result "m=eight" takes place regardless of what n is, and the "else" is an unlawful statement since it appears to be with out an "if". To institution the two statements together, you want to frame them the usage of braces: if (n>three) response = "large"; m = eight; else reaction = "Small"; The braces organization the two statements together into a block. some programmers (including me) prefer an alternative manner of writing this15: if (n>3) reaction = "massive"; m = 8;

else response = "Small"; Blocks can be nested. in the following, the block containing m=8; is nested in the block for the if (n>three): if (n>three) response = "huge"; if (q == 1) m = eight;   right here is some thing to put in writing at the back of your hand: Variables are valid simplest in the block wherein they're defined. consequently the subsequent might not work: String reaction; boolean sure = fake; if (n>three) int m; reaction = "huge"; if (q == 1) m = 8; boolean sure = genuine;   m = m + 2; if (yes) device.out.println("yes!!!"); In fact, that is pretty badly screwed up. The String response is diagnosed throughout this code. The integer m, but, is declared within the block for (n>three), and as a result it is not legitimate out of doors the block, and hence the announcement m = m + 2 is coping with a variable that looks to be undefined. The compiler will give an mistakes. The boolean sure is declared twice, as soon as outdoor the first if and as soon as in the nested block. those are dealt with as separate variables, with the internal "sure" understood best within the internal block!!! hence, the price of the outer "yes" at the give up may be fake!

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.