how to implement threads in c

how to implement threads in c

Pthreads are a simple and effective way of creating a multi-threaded application. 

When a thread is created using pthread_create, both the original thread and the new thread share the same code base and the same memory – it’s just like making two function calls at the same time.

All C programs using pthreads need to include the pthread.h header file.

#include<stdio.h>
#include<pthread.h>

pthread_t thread[2];


static void *function1(void *_){

 int i;
 for(i=0;i<10;i++){
  printf("\nThread1 says=%d",i);
  sleep(1);

}
}

static void *function2(void *_){

 int i;
 for(i=0;i<5;i++){

  printf("\nThread2 says=%d",i);
  sleep(5);
}
}

int main(){

    pthread_create(&thread[0], NULL , function1, NULL);
    pthread_create(&thread[1], NULL , function2, NULL);

    pthread_exit(NULL);
return 1;
}

NQueen Problem in C

 NQueen Problem in C

 

#include<stdio.h>
#include<math.h>
#define TRUE 1
#define FALSE 0
#define MAXBOARDSIZE 8
int board[MAXBOARDSIZE];
int n;
int steps;
static int solno=1;
void PrintBoard()
{
    int i, k,z;

    printf("\nSolution %d:\n", solno++);
    printf("No of Steps=%d:\n", steps);
    for (i = 0; i < n; i++)
    {
        for (k = 0; k < board[i]; k++)
            printf("\t-");
        printf("\tQ%d",i+1);
        for(z=k;z<n-1;z++)
            printf("\t-");
        printf("\n");
    }
}

int IsPlaceSafe(int row, int col)
{
    int i;

    for(i=0; i<row; i++)
    {
        if( (board[i] == col) || (abs(board[i]-col) == abs(i-row)) )
            return FALSE;
    }
    return TRUE;
}

void NQueens(int row)
{
    int col;
    for(col=0; col<n; col++)
    {
        steps++;
        if(IsPlaceSafe(row, col))
        {
            board[row] = col;
            if(row == n-1)
                PrintBoard();
            else
                NQueens(row+1);
        }
    }
}

int main()
{ 
    int c=1;
    while(c==1){
    printf("Enter board size: ");
    scanf("%d", &n);
    if(n>MAXBOARDSIZE || n<4){
     printf("\nNo Solution Exit\n");
    }else{
    NQueens(0);
    }
    printf("\nPress 1 to Continue and 0 to exit");
    scanf("%d",&c);
    solno=1;
    steps=0;
    }
    return 0;
}

DFA implementation in java

DFA implementation in java

--------APP CLASS--------

import java.awt.Color;

import java.awt.Cursor;

import java.awt.Font;

import java.awt.List;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.image.BufferedImage;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileReader;

import java.io.IOException;

import java.util.ArrayList;

import javax.imageio.ImageIO;

import javax.swing.*;

public class App {

JFrame f1,f2,f3,f4,f5,f_dailog;

JButton JB_dfa,JB_nfa,JB_new,JB_select,JB_cDFA[];

String path="";

ArrayList<String> records;

int TT[][];

int start_state=0,final_state=0,no_state=0,no_var=0;

String inputString="";

DFA obj_DFA;

public App(){

f1=new JFrame();

f1.setSize(600, 420);

f1.setVisible(true);

f1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f1.setResizable(false);

f1.setLocationRelativeTo(null);

f1.setLayout(null);

f1.setTitle("FINITE AUTOMATA | DEVELOPED BY SHAHARYAR SHAUKAT");

try{

BufferedImage bf = ImageIO.read(new File("icon//BG1.png"));  

f1.setContentPane(new Bg(bf));

}catch(Exception e){

}

JB_dfa=new JButton("DFA");

JB_dfa.setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_dfa.setBounds(50, 200, 80, 50);

JB_dfa.setBackground(new Color(109, 183, 246));

JB_dfa.setForeground(new Color(255,255,255));

JB_dfa.setFont(new Font("Garamond",  Font.BOLD , 20));

f1.add(JB_dfa);

JB_dfa.addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

f2.setVisible(true);

f1.setVisible(false);

}

});

JB_nfa=new JButton("NFA");

JB_nfa.setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_nfa.setBounds(200, 200, 80, 50);

JB_nfa.setBackground(new Color(109, 183, 246));

JB_nfa.setForeground(new Color(255,255,255));

JB_nfa.setFont(new Font("Garamond",  Font.BOLD , 20));

f1.add(JB_nfa);

JB_nfa.addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

}

});

f1.validate();

// FRAME 2

f2=new JFrame();

f2.setSize(600, 420);

f2.setVisible(false);

f2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f2.setResizable(false);

f2.setLocationRelativeTo(null);

f2.setLayout(null);

f2.setTitle("FINITE AUTOMATA | DEVELOPED BY SHAHARYAR SHAUKAT");

try{

BufferedImage bf = ImageIO.read(new File("icon//BG1.png"));  

f2.setContentPane(new Bg(bf));

}catch(Exception e){

}

JB_new=new JButton("CREATE NEW DFA");

JB_new.setToolTipText(" Provide Transition Table ");

JB_new.setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_new.setBounds(30, 120, 300, 50);

JB_new.setBackground(new Color(109, 183, 246));

JB_new.setForeground(new Color(255,255,255));

JB_new.setFont(new Font("Garamond",  Font.BOLD , 25));

JB_new.addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

f_dailog.setVisible(true);

}

});

f2.add(JB_new);

JB_select=new JButton("SELECT  DFA");

JB_select.setToolTipText(" Select Sample DFA From given List  ");

JB_select.setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_select.setBounds(30, 220, 300, 50);

JB_select.setBackground(new Color(109, 183, 246));

JB_select.setForeground(new Color(255,255,255));

JB_select.setFont(new Font("Garamond",  Font.BOLD , 25));

JB_select.addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

f2.setVisible(false);

f3.setVisible(true);

}

});

f2.add(JB_select);

// USER INPUT 

f_dailog=new JFrame("");

f_dailog.setSize(300, 200);

f_dailog.setVisible(false);

f_dailog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

f_dailog.setResizable(false);

f_dailog.setLocationRelativeTo(null);

f_dailog.setLayout(null);

JLabel lbl_noState=new JLabel("NO. of States");

lbl_noState.setBounds(10, 10, 80, 40);

JTextField txt_noState=new JTextField();

txt_noState.setBounds(90, 10, 40, 40);

JLabel lbl_noVar=new JLabel("NO. of Var");

lbl_noVar.setBounds(160, 10, 80, 40);

JTextField txt_noVar=new JTextField();

txt_noVar.setBounds(220, 10, 40, 40);

f_dailog.add(lbl_noState);

f_dailog.add(lbl_noVar);

f_dailog.add(txt_noState);

f_dailog.add(txt_noVar);

//FRAME 3 Pre selected

f3=new JFrame();

f3.setSize(600, 420);

f3.setVisible(false);

f3.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f3.setResizable(false);

f3.setLocationRelativeTo(null);

f3.setLayout(null);

f3.setTitle("FINITE AUTOMATA | DEVELOPED BY SHAHARYAR SHAUKAT");

try{

BufferedImage bf = ImageIO.read(new File("icon//BG1.png"));  

f3.setContentPane(new Bg(bf));

}catch(Exception e){

}

JB_cDFA=new JButton[5];

JB_cDFA[0]=new JButton("DFA that accepts all string which occur with even no. of 0s and 1s");

JB_cDFA[0].setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_cDFA[0].setBounds(5, 100, 350, 30);

JB_cDFA[0].setBackground(new Color(109, 183, 246));

JB_cDFA[0].setForeground(new Color(255,255,255));

JB_cDFA[0].setFont(new Font("Garamond",  Font.BOLD , 9));

JB_cDFA[0].addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

path="files//0.txt";

readFile(path);

f3.setVisible(false);

f5.setVisible(true);

System.out.println("");

for(int i=0;i<records.size();i++){

System.out.println(records.get(i));

}

System.out.println("------------");

System.out.println("no-states"+no_state);

System.out.println("start_states"+start_state);

System.out.println("final-states"+final_state);

System.out.println("no_var="+no_var);

System.out.println("--------------");

for(int i=0;i<no_state;i++){

System.out.print("\t"+TT[i][0]);

System.out.print("\t"+TT[i][1]);

System.out.print("\n");

}

obj_DFA=new DFA(TT,start_state,final_state,no_state,no_var);

Display obj_Display=new Display(TT);

obj_Display.setBounds(10, 100, 980, 480);

f5.add(obj_Display);

Thread t_Display=new Thread(obj_Display);

t_Display.start();

}

});

f3.add(JB_cDFA[0]);

JB_cDFA[1]=new JButton("DFA that accepts all string which ends with 0 and 1");

JB_cDFA[1].setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_cDFA[1].setBounds(5, 150, 350, 30);

JB_cDFA[1].setBackground(new Color(109, 183, 246));

JB_cDFA[1].setForeground(new Color(255,255,255));

JB_cDFA[1].setFont(new Font("Garamond",  Font.BOLD , 9));

JB_cDFA[1].addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

path="files//1.txt";

readFile(path);

f3.setVisible(false);

f5.setVisible(true);

System.out.println("");

for(int i=0;i<records.size();i++){

System.out.println(records.get(i));

}

System.out.println("------------");

System.out.println("no-states"+no_state);

System.out.println("start_states"+start_state);

System.out.println("final-states"+final_state);

System.out.println("no_var="+no_var);

System.out.println("--------------");

for(int i=0;i<no_state;i++){

System.out.print("\t"+TT[i][0]);

System.out.print("\t"+TT[i][1]);

System.out.print("\n");

}

obj_DFA=new DFA(TT,start_state,final_state,no_state,no_var);

Display obj_Display=new Display(TT);

obj_Display.setBounds(10, 100, 980, 480);

f5.add(obj_Display);

Thread t_Display=new Thread(obj_Display);

t_Display.start();

}

});

f3.add(JB_cDFA[1]);

JB_cDFA[2]=new JButton("DFA that accepts all string which have 2nd last symbol is 1");

JB_cDFA[2].setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_cDFA[2].setBounds(5, 200, 350, 30);

JB_cDFA[2].setBackground(new Color(109, 183, 246));

JB_cDFA[2].setForeground(new Color(255,255,255));

JB_cDFA[2].setFont(new Font("Garamond",  Font.BOLD , 9));

f3.add(JB_cDFA[2]);

JB_cDFA[3]=new JButton("DFA that accepts all string which have 011 as substring");

JB_cDFA[3].setCursor(new Cursor(Cursor.HAND_CURSOR));

JB_cDFA[3].setBounds(5, 250, 350, 30);

JB_cDFA[3].setBackground(new Color(109, 183, 246));

JB_cDFA[3].setForeground(new Color(255,255,255));

JB_cDFA[3].setFont(new Font("Garamond",  Font.BOLD , 9));

f3.add(JB_cDFA[3]);

// DISPLAY FRAME

f5=new JFrame();

f5.setSize(1000, 600);

f5.setVisible(false);

f5.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f5.setResizable(false);

f5.setLocationRelativeTo(null);

f5.setLayout(null);

f5.setTitle("FINITE AUTOMATA | DEVELOPED BY SHAHARYAR SHAUKAT");

final JTextField input=new JTextField();

JButton start=new JButton("START");

start.setCursor(new Cursor(Cursor.HAND_CURSOR));

start.setBounds(30, 10, 120, 50);

start.setBackground(new Color(109, 183, 246));

start.setForeground(new Color(255,255,255));

start.setFont(new Font("Garamond",  Font.BOLD , 20));

start.addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

inputString=input.getText();

System.out.println(inputString);

obj_DFA.input=inputString;

Thread t_DFA=new Thread(obj_DFA);

t_DFA.start();

}

});

f5.add(start);

JButton pause=new JButton("PAUSE");

pause.setCursor(new Cursor(Cursor.HAND_CURSOR));

pause.setBounds(850, 10, 120, 50);

pause.setBackground(new Color(109, 183, 246));

pause.setForeground(new Color(255,255,255));

pause.setFont(new Font("Garamond",  Font.BOLD , 20));

pause.addActionListener(new ActionListener(){

@Override

public void actionPerformed(ActionEvent arg0) {

// TODO Auto-generated method stub

}

});

f5.add(pause);

input.setBounds(200, 10, 600, 50);

input.setFont(new Font("SansSerif", Font.BOLD, 25));

f5.add(input);

}

public static void main(String args[]){

new App();

}

public void readFile(String filename)

{

 records = new ArrayList<String>();

 try

 {

   BufferedReader reader = new BufferedReader(new FileReader(filename));

   String line;

   while ((line = reader.readLine()) != null)

   {

     records.add(line);

   }

   reader.close();

   storeValue();

   

 }

 catch (Exception e)

 {

   System.err.format("Exception occurred trying to read '%s'.", filename);

   e.printStackTrace();

  

 }

}

//

public void storeValue(){

no_state=records.size()-2;

start_state=records.get(0).charAt(1)-48;

final_state=records.get(1).charAt(1)-48;

no_var=records.get(2).trim().split("\\s+").length;

TT=new int[no_state][no_var];

for(int i=0;i<no_state;i++){

String[] words=records.get(i+2).split("\\s+");

for(int j=0;j<2;j++){

TT[i][0]=words[0].charAt(1)-48;

TT[i][1]=words[1].charAt(1)-48;

}

}

}

// End Class

}

----------------DFA CLASS--------------

public class DFA implements Runnable {

int TT[][];

static String input="";

static int start_state=0,final_state=0,no_state=0,no_var=0;

public static int present_state=0;

static int result=3,ptr=0;

public DFA(){

}

public DFA(int TT[][],int start_state ,int final_state ,int no_state,int no_var){

this.TT=TT;

this.start_state=start_state;

this.final_state=final_state;

this.no_state=no_state;

this.no_var=no_var;

present_state=start_state;

}

@Override

public void run() {

// TODO Auto-generated method stub

   result=0;

Algo();

}

public void Algo(){

for(int i=0;i<input.length();i++){

ptr=i;

char ch=input.charAt(i);

int ch_value=(int)ch-48;

int temp_state=present_state;

present_state=TT[temp_state][ch_value];

try {

Thread.sleep(1500);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

if(present_state==final_state){

System.out.println("ACCEPTED");

result=1;

}else{

System.out.println("NOT ACCEPTED");

result=2;

}

}

}

------------BG CLASS----------

import java.awt.Graphics;

import java.awt.Image;

import javax.swing.JComponent;

public class Bg extends JComponent {

Image i;

public Bg(Image i) {

this.i = i;

}

public void paintComponent(Graphics g) {

g.drawImage(i, 0, 0, null);  // Drawing image using drawImage method

 

}

}