2D Parity Checking

#include<iostream>

#include<stdlib.h>

using namespace std;

#define maxlength 10

#define maxmessages 10

void initialize(int arr[][10],int m,int n)

{

for(int i =0;i<m;i++)

for(int j=0;j<n;j++)

{

arr[i][j] = rand()%2;

}

}

void print(int arr[][10],int m,int n)

{

for(int i =0;i<m;i++)

{  for(int j=0;j<n;j++)

{

cout<<arr[i][j]<<” “;

}

cout<<endl;

}

}

void addparbit(int arr[][10],int m,int n)  // Even Parity

{

for(int i=0;i<m;i++)

{

int count = 0;

for(int j=0;j<n;j++)

{

if(arr[i][j] == 1)

count++;

}

if(count%2 == 0)

arr[i][n] = 0;

else

arr[i][n] = 1;

}

}

void induceerror(int arr[][10],int m,int n)

{

int k1,k2;

k1= rand()%m;

k2 = rand()%n;

if(arr[k1][k2]==0)

arr[k1][k2]=1;

else

arr[k1][k2]=0;

cout<<“Inducing error at line : “<<k1<<endl;

}

void checkerror(int arr[][10],int m,int n)

{

for(int i=0;i<m;i++)

{

int count = 0;

for(int j=0;j<n;j++)

{

if(arr[i][j] == 1)

count++;

}

if(count%2 == 0 && arr[i][n] != 0)

{

cout<<“Error here at line : ” <<i;

}

else if(count%2 == 1 && arr[i][n] != 1)

{

cout<<“Error here at line : ” <<i;

}

 

}

}

 

int main()

{   int m,n,arr[maxmessages][maxlength];

cout<<“Enter total number of messages”;

cin>>m;

cout<<“Enter length of each message”;

cin>>n;

initialize(arr,m,n);

print(arr,m,n);

addparbit(arr,m,n);

print(arr,m,n+1);

induceerror(arr,m,n);

print(arr,m,n+1);

checkerror(arr,m,n);

return 0;

}

 

 

 

Arithmetic Coding

#include<iostream.h>

#include<stdio.h>

#include<conio.h>

struct node

{

char ch;

float start,end;

float p;

}n[30];

void sort(node n[], int m)

{

node temp;

//float small=n[0].p;

//int pos=0;

for(int i=0;i<m-1;i++)

{

for(int j=i+1;j<m;j++)

{

if(n[i].p<n[j].p)

{

temp=n[j];

n[j]=n[i];

n[i]=temp;

}

}

}

cout<<“\nSorted array is”;

for( i=0;i<m;i++)

{

cout<<“\n”<<n[i].ch;

}

}

void getpoint(node n[], int m)

{       int i=0;

n[0].start=0.0;

//int i=0;

for(int k=1;k<m;k++)

{

n[i].end=n[i].start+n[i].p;

n[k].start=n[i].end;

i++;

}

k–;

n[k].end=1.0;

}

node check(node n[],int m, char c)

{ node temp;

for(int i=0;i<m;i++)

{

if(c==n[i].ch)

{

temp=n[i];

}

}

return temp;

}

void display(node n[],int m)

{

for(int h=0;h<m;h++)

{

cout<<“\n character”<<n[h].ch;

cout<<“\n start point”<<n[h].start;

cout<<“\n end point”<<n[h].end;

}

}

void calc(node n[],int m,node x,float a)

{

n[0].start=x.start;

int i=0;

for(int k=1;k<m;k++)

{

n[i].end=n[i].start+n[i].p*a;

n[k].start=n[i].end;

i++;

}

k–;

n[k].end=x.end;

}

void main()

{

clrscr();

int m;

cout<<“enter the size of array”;

cin>>m;

cout<<“enter”;

for(int i=0;i<m;i++)

{

cin>>n[i].ch;

cout<<“\n p ??”;

cin>>n[i].p;

n[i].start=n[i].end=0.0;

}

sort(n,m);

getpoint(n,m);

display(n,m);

char str[30];

cout<<“enter string”;

gets(str);

fflush(stdin);

node x;

float a;

a=1;

for(i=0;i<m-1;i++)

{

clrscr();

x=check(n,m,str[i]);

a=x.end-x.start;

calc(n,m,x,a);

display(n,m);

getch();

}

cout<<“\n”<<n[m-1].start<<“_>”<<n[m-1].end;

getch();

}

 

 

Run Length Encoding

#include<iostream.h>

#include<conio.h>

#include<stdio.h>

#include<string.h>

int getcount(char str[],int i,int j)

{ int count=1;

while(str[i]==str[j])

{

count++;

j++;

}

return count;

}

void display(char str[],int i,int c)

{

if(c>3)

{

cout<<“!”<<c<<” “<<str[i];

}

else

{

for(int j=0;j<c;j++)

{

cout<<“\t “<<str[i];

}

}

}

void main()

{

clrscr();

char str[30];

int m;

cout<<“enter string”;

gets(str);

fflush(stdin);

m=strlen(str);

int i=0;

int c,j;

while(i<m)

{

j=i+1;

if(str[i]==str[j])

{

c=getcount(str,i,j);

display(str,i,c);

i=i+c;

}

else

{

cout<<“\t”<<str[i];

i++;

}

}

getch();

}

 

Theory:

http://netghost.narod.ru/gff/graphics/book/ch09_03.htm