- //Nicholas Riseden
-
//CSCI 3300
-
//Assignment 4 Version 2
-
-
#include "tree.h"
-
#include "pqueue.h"
-
#include <string>
-
#include <fstream>
-
#include <iostream>
-
#include <stdio.h>
-
#include "binary1.h"
-
-
using namespace std;
-
-
/*****************************************************************
-
* buildTree *
-
******************************************************************
-
* buildTree takes the array built from getFrequency and builds a *
-
* tree that holds a character and its priority using the insert *
-
* function. *
-
* *
-
* For example, if the file reads "AAb" it creates a node for the *
-
* character 'A' and stores its priority 2 for that node. *
-
*****************************************************************/
-
Node* buildTree(int arrayOfInts[])
-
{
-
PriorityQueue q;
-
for(int x = 0; x <= 255; x++)
-
{
-
if(arrayOfInts[x]!=0)
-
{
-
Node* leaf = new Node((char)x);
-
insert(q, leaf, arrayOfInts[x]);
-
}
-
}
-
-
Node* t1,*t2;
-
int p1, p2;
-
remove(q, t1, p1);
-
-
while(isEmpty(q)==false)
-
{
-
remove(q,t2, p2);
-
Node* t3 = new Node(t1, t2);
-
insert(q, t3, (p1 +p2));
-
remove(q, t1, p1);
-
}
-
-
return t1;
-
}
-
-
/*****************************************************************
-
* getFrequency *
-
******************************************************************
-
* getFrequency takes an array of 256 integers. It opens a *
-
* file and counts the amount of character *
-
* frequencies that occur, storing that count into the position *
-
* in the array that correpsonds with the character's *
-
* Ascii value. *
-
* *
-
* For example, if the file reads "AAb" it stores the number 2 in *
-
* position 64 in the array since capital A is a 65 on the Ascii *
-
* chart and arrays are zero based. *
-
*****************************************************************/
-
-
int* getFrequency(char* filename, int arrayOfInts[])
-
{
-
ifstream in;
-
in.open(filename);
-
for(int i = 0; i < 256; i++)
-
{
-
arrayOfInts[i] = 0;
-
}
-
-
-
-
int c = in.get();
-
-
while(c!=EOF)
-
{
-
arrayOfInts[c]++;
-
c = in.get();
-
}
-
-
int count = 0;
-
cout<<"\nThe character frequencies are: \n\n";
-
int k = 0;
-
while(k < 256)
-
{
-
-
if(k>0)
-
{
-
-
if(k == 10)
-
{
-
cout<<"\\n "<<arrayOfInts[k]<<"\n";
-
}
-
else if(k!=10)
-
{
-
cout<<char(k)<< " "<<arrayOfInts[k]<<"\n";
-
}
-
}
-
-
-
count++;
-
cout<<"count is "<<count<<"\n";//count reaches 256, then segmentation fault is printed
-
k++;
-
}
-
-
in.close();
-
cout<<"This is sparta\n";
-
return arrayOfInts;
-
cout<< "This is over\n";
-
-
}
-
-
//comments to describe this function
-
void writeTree(BFILE* f, Node* t)
-
{
-
if(t->kind!=leaf)
-
{
-
writeBit(f, 0);
-
writeTree(f, t->left);
-
writeTree(f, t->right);
-
}
-
else
-
{
-
writeBit(f, 1);
-
writeByte(f, t->ch);
-
}
-
-
-
}
-
//buildcode
-
void buildCode(Node* n, string codeArray[], string pref)
-
{
-
if(n->kind == leaf)
-
{
-
codeArray[int(n->ch)] = pref;
-
}
-
else if(n->kind == nonleaf)
-
{
-
buildCode(n->left, codeArray, pref + "0");
-
buildCode(n->right, codeArray, pref + "1");
-
}
-
-
}
-
//writecode(f, str) writes string str to BFILE* f, one bit
-
//at a time.
-
void writeCode(BFILE* f, string str)
-
{
-
int y = str.length();
-
for(int x = 0; x < y; x++)
-
{
-
writeBit(f, str[x]);
-
}
-
-
}
-
-
//function description
-
void writeCodedFile(char* filename, string codearray[], BFILE* f)
-
{
-
ifstream in;
-
in.open(filename);
-
int c = cin.get();
-
while(c != EOF)
-
{
-
writeCode(f, codearray[c]);
-
c = cin.get();
-
}
-
cout<<"Test E";
-
in.close();
-
}
-
-
-
int main(int argc, char* argv[])
-
{
-
string codeArray[255];
-
int arrayOfInts[255];
-
int* frequencyArray = getFrequency(argv[1], arrayOfInts);//problem is here
-
cout<<"I am about to do buildTree.";//this never gets printed
-
Node* n = buildTree(frequencyArray);
-
cout<<"I am done buildTree.";//this never gets printed
-
buildCode(n, codeArray, "");
-
-
BFILE* f = openBinaryFileWrite(argv[2]);
-
-
writeTree(f,n);
-
-
writeCodedFile(argv[1], codeArray,f);
-
-
closeBinaryFileWrite(f);
-
-
return 0;
-
-
}
18 2999 Frinavale 9,735
Recognized Expert Moderator Expert
In the future could you please only post the code that is relevant to the problem. It's unfair to expect people to sift through tons of code to find the few lines that you are having problems with.
Also, in the future, please specify what you are having problems with, what (if any) errors you are getting, and what you have tried to solve the problem. Don't just post a bunch of code and expect us to figure out what it is, what's wrong with it, and what you are having problems with.
Please check out the posting guidelines for more information on how to ask a question.
A segmentation fault occurs when a program attempts to access a memory location that it is not allowed to access, or attempts to access a memory location in a way that is not allowed (for example, attempting to write to a read-only location, or to overwrite part of the operating system).
This means that somewhere in your code you are attempting to access memory that your application is not allowed to access. It's likely that you're moving through an array and going past the end of it...
-Frinny
never mind my post, reshifted your code and my comment was incorrect.
Try providing the error message and line number if possible, helps alot
check on whether char is signed or unsigned by default
/s/ Jim WIlliams
I thought the whole code was necessary to understand what was going on. I apologize if anyone else other than "Frinny" had an issue with me posting. Anyways,here is the code where the actual problem was. -
/*****************************************************************
-
* getFrequency *
-
******************************************************************
-
* getFrequency takes an array of 256 integers. It opens a *
-
* file and counts the amount of character *
-
* frequencies that occur, storing that count into the position *
-
* in the array that correpsonds with the character's *
-
* Ascii value. *
-
* *
-
* For example, if the file reads "AAb" it stores the number 2 in *
-
* position 64 in the array since capital A is a 65 on the Ascii *
-
* chart and arrays are zero based. *
-
*****************************************************************/
-
-
int* getFrequency(char* filename, int arrayOfInts[])
-
{
-
ifstream in;
-
in.open(filename);
-
for(int i = 0; i < 257; i++)
-
{
-
arrayOfInts[i] = 0;
-
}
-
-
-
-
int c = in.get();
-
-
while(c!=EOF)
-
{
-
arrayOfInts[c]++;
-
c = in.get();
-
}
-
-
int count = 0;
-
-
cout<<"\nThe character frequencies are: \n\n";
-
while(count < 257)
-
{
-
while(arrayOfInts[count]!=0)
-
{
-
if(count == 10)
-
{
-
cout<<"\\n "<<arrayOfInts[count]<<"\n";
-
count++;
-
}
-
else
-
{
-
cout<<char(count)<< " "<<arrayOfInts[count]<<"\n";
-
count++;
-
}
-
}
-
-
count++;
-
-
}
-
-
in.close();
-
-
return arrayOfInts;
-
-
-
}
It prints the character frequencies, then a segmentation fault. The array should be 256 characters to hold each printable character. Any ideas?
Frinavale 9,735
Recognized Expert Moderator Expert
I'm sorry if I came across a bit strong yesterday. I was seeing a lot of threads where people would just post a bunch of code and title the thread "what's wrong with this code". Needless to say that I was pretty frustrated by the time I came across yours.
I'm glad that you were able to narrow it down a bit for us.
I think that the problem is occurring within this loop: - while(c!=EOF)
-
{
-
arrayOfInts[c]++;
-
c = in.get();
-
}
You should check to make sure that "c" is a valid index before you do what you're doing.
Try the following: - while(c!=EOF)
-
{ if(c>=0 && c<=256)
-
{
-
arrayOfInts[c]++;
-
}
-
c = in.get();
-
}
-Frinny
Frinavale 9,735
Recognized Expert Moderator Expert
Um I take it back. It might be the loop that prints the values.
What are you doing in the loop that prints the values!
Why don't you just use for( count=0; count<=256; count++)???
I did. I changed it to a for loop and changed the other thing you suggested and I am still hitting a segmentation fault. Here is what I have now for reference. -
int* getFrequency(char* filename, int arrayOfInts[])
-
{
-
ifstream in;
-
in.open(filename);
-
for(int i = 0; i < 256; i++)
-
{
-
arrayOfInts[i] = 0;
-
}
-
-
-
-
int c = in.get();
-
-
while(c!=EOF)
-
{
-
if(c>0 && c<=256)
-
{
-
arrayOfInts[c]++;
-
}
-
c = in.get();
-
}
-
-
-
-
cout<<"\nThe character frequencies are: \n\n";
-
for(int count = 0; count<=256; count++)
-
{
-
while(arrayOfInts[count]!=0)
-
{
-
if(count == 10)
-
{
-
cout<<"\\n "<<arrayOfInts[count]<<"\n";
-
count++;
-
}
-
else
-
{
-
cout<<char(count)<< " "<<arrayOfInts[count]<<"\n";
-
count++;
-
}
-
}
-
cout<<count<<"\n";
-
count++;
-
-
}
-
-
in.close();
-
-
return arrayOfInts;
-
-
-
}
Because your array has only 255 elements, the max index is 254. So the loop must be like this - for(int count = 0; count <= 254; count++)
or - for(int count = 0; count != 255; count++)
You get segmentation fault when you access the element that is not in array
Which loop do I need that for in the above function? All of them? I tried changing all of the conditions for the loops like you said and I am still receiving the segmentation fault.
Sign in to post your reply or Sign up for a free account.
Similar topics |
by: Jay donnell |
last post by:
I have a short multi-threaded script that checks web images to make
sure they are still there. I get a segmentation fault everytime I run
it and I can't figure out why. Writing threaded scripts is new to me so
I may be doing something wrong that should be obvious :(
google messes up the python code so here is a link to it.
http://kracomp.com/~jay/py.txt
This is the output of the script.
|
by: fudmore |
last post by:
Hello Everybody.
I have a Segmentation fault problem. The code section at the bottom
keeps throwing a Segmentation fault when it enters the IF block for the
second time.
const int WORDS_PER_LINE = 4;
when counter == 7 is when the string Concatenation fails within the IF
block.
|
by: Polar |
last post by:
Hi!
i'm a newbie in C language and i'm writing my first simple codes.
In one of these, my purpose is to append the ascii value of an interger
(example 101 --> e) at the end of a string to obtain a new (longer)
string. Example:
string: languag
letter: e
|
by: damian birchler |
last post by:
If I run the following I get a segmentation fault:
#define NAMELEN 15
#define NPERS 10
typedef struct pers {
char name;
int money;
} pers_t;
|
by: I_have_nothing |
last post by:
Hi!
I am new in C. I try to use dynamical allocation fuction malloc( ) and
realloc( ).
I found something strange.
After several calling realloc( ), the malloc( ) will give me a
Segmentation fault.
If I just call realloc( ) once before calling malloc( ), it is OK.
Why?
I am trying to read some double-typed items from infile and save them
| |
by: Fra-it |
last post by:
Hi everybody,
I'm trying to make the following code running properly, but I can't get
rid of the "SEGMENTATION FAULT" error message when executing.
Reading some messages posted earlier, I understood that a segmentation
fault can occur whenever I declare a pointer and I leave it
un-initialized.
So I thought the problem here is with the (const char *)s in the stuct
flightData (please note that I get the same fault declaring as char *
the...
|
by: Paminu |
last post by:
I have a wierd problem.
In my main function I print "test" as the first thing. But if I run the call
to node_alloc AFTER the printf call I get a segmentation fault and test is
not printed!
#include <stdlib.h>
#include <stdio.h>
typedef struct _node_t {
|
by: pycraze |
last post by:
I would like to ask a question. How do one handle the exception due to
Segmentation fault due to Python ? Our bit operations and arithmetic
manipulations are written in C and to some of our testcases we
experiance Segmentation fault from the python libraries.
If i know how to handle the exception for Segmentation fault , it will
help me complete the run on any testcase , even if i experiance Seg
Fault due to any one or many functions in...
|
by: madunix |
last post by:
My Server is suffering bad lag (High Utlization)
I am running on that server Oracle10g with apache_1.3.35/ php-4.4.2
Web visitors retrieve data from the web by php calls through oci
cobnnection from 10g release2
PHP is configured with the following parameters
'./configure' '--prefix=/opt/oracle/php'
'--with-apxs=/opt/oracle/apache/bin/apxs'
'--with-config-file-path=/opt/oracle/apache/conf' '--enable-safe-mode'
'--enable-session'...
|
by: DanielJohnson |
last post by:
int main()
{
printf("\n Hello World");
main;
return 0;
}
This program terminate just after one loop while the second program
goes on infinitely untill segmentation fault (core dumped) on gcc. The
only difference is that in first I only call "main" and in second call
|
by: marktang |
last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However, people are often confused as to whether an ONU can Work As a Router. In this blog post, we’ll explore What is ONU, What Is Router, ONU & Router’s main usage, and What is the difference between ONU and Router. Let’s take a closer look !
Part I. Meaning of...
| |
by: Hystou |
last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can effortlessly switch the default language on Windows 10 without reinstalling. I'll walk you through it.
First, let's disable language synchronization. With a Microsoft account, language settings sync across devices. To prevent any complications,...
|
by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
|
by: Hystou |
last post by:
Overview:
Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows Update option using the Control Panel or Settings app; it automatically checks for updates and installs any it finds, whether you like it or not. For most users, this new feature is actually very convenient. If you want to control the update process,...
|
by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
|
by: agi2029 |
last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing, and deployment—without human intervention. Imagine an AI that can take a project description, break it down, write the code, debug it, and then launch it, all on its own....
Now, this would greatly impact the work of software developers. The idea...
|
by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
| |
by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
|
by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
| |