Simple Java Program to Demonstrate Class and Objects

Design a STUDENT class to store roll,name,admission date and marks in 5 subjects taken from user. Create an array of STUDENT objects. Provide methods corresponding to admission date and receiving marks, preparing mark sheet. Support also must be there to show number of students who have taken admission.

import java.util.*;
public class Student
    {
    public static void main(String[] args)
    {
      int[] mdays={31,28,31,30,31,30,31,31,30,31,30,31};
int[] ldays={31,29,31,30,31,30,31,31,30,31,30,31};
int ch,n;
String d1;
boolean lp,fg=true;
    Scanner in = new Scanner(System.in);
        StudentRecord[] students = new StudentRecord[6];
        Course co = new Course();
        System.out.println("Courses available are Graduation, PG and PhD with 3,2 and 1 seats respectively:");
        for(int i=0;i<6;i++)
    students[i]=new StudentRecord();
    String choice1="YES";
    int k=0;
    do
    {
   
    System.out.println("\n Enter the course name:");
    String S = in.next();
    if(co.getCourse(S).equals("XX"))
    {
    System.out.println("Invalid course:");
    continue;
    }
    if(co.getSeat(S)>co.getSeatLimit(S))
    {
    System.out.println("Seats for the course "+S+" is exhausted:");
    continue;
    }
      System.out.println("Enter the Record for student :"+(k+1));
      students[k].setCourse(S);
    students[k].inputData();
    k++;
    System.out.println(" Want to add another record yes/no:");
    choice1 = in.next();
    }while("YES".equalsIgnoreCase(choice1));
    n=k;
    System.out.println("Press 1 to display Records of all STUDENTS:");
    System.out.println("Press 2 to see the result of all STUDENTS:");
    ch = in.nextInt();
    switch(ch)
    {
    case 1:
    for(int i=0;i<n;i++)
    students[i].displayAll();
    break;
    case 2:
        for(int i=0;i<n;i++)
        students[i].resultBuild();
        break;
        default:
        System.out.println("Wrong choice:");
        break;
        }
        System.out.println(" Want to search by Admission Date(dd/mm/yyyy)? yes/no:");
        String choice = in.next();
        if("YES".equalsIgnoreCase(choice))
        {
        int d=0,m=0,y=0;
         
          do {
fg=true;
int i=0;
int j=0;

String temp ="";
System.out.println("Enter the admission date(dd/mm/yyyy):");
d1=in.next();
while(d1.charAt(i)!='/' && i<d1.length())
{
if(0 <= d1.charAt(i)-48 && d1.charAt(i)-48 <= 9 )
{
temp=temp+d1.charAt(i);
i++;
j++;
}
else
{
System.out.println("Incorrect format:");
i++;
fg=false;
break;
}
} //d extraction
//System.out.println("Temp="+temp+"I="+i+"J="+j+"fg="+fg);
  if(fg==true && j<=2 && d1.charAt(i)=='/' && j >0 )
{
j=0;
d = Integer.valueOf(temp);
i=i+1;
temp="";
while(d1.charAt(i)!='/' && i<d1.length() )
{
if(0 <= d1.charAt(i)-48 && d1.charAt(i)-48 <= 9 )
{
temp=temp+d1.charAt(i);
i++;
j++;
}
else
{
System.out.println("Incorrect format:");
i++;
//j++;
fg=false;
break;
}
} //m extraction
m = Integer.valueOf(temp);
}
//System.out.println("Temp="+temp+"I="+i+"J="+j+"fg="+fg);

if(fg==true && j<=2 && d1.charAt(i)=='/' && j >0 && m <=12 && 1<=m)
{
j=0;
//m = Integer.valueOf(temp);
//System.out.println(d);
i=i+1;
temp="";
while(i<d1.length())
{
if(0 <= d1.charAt(i)-48 && d1.charAt(i)-48 <= 9 )
{
temp=temp+d1.charAt(i);
i++;
j++;
}
else
{
System.out.println("Incorrect format:");
fg=false;
i++;
break;
//j++;

}
} //y extraction
}
//System.out.println("Temp="+temp+"I="+i+"J="+j+"fg="+fg);
if(fg==true && j==4)
{
y = Integer.valueOf(temp);
fg=true;
}//end of else of y
else
fg=false;
if(fg==true)
{
if(y%400==0)
    lp=true;
else if (y%100==0)
    lp=false;
else if (y%4==0)
    lp=true;
else
    lp=false;
   
if(lp==false)
{
if(d>mdays[m-1] || d < 1 )
{
System.out.println("Invalid d of a m:");
fg=false;
}
}//non-lp y checking
else
{
if(d>ldays[m-1] || d < 1)
{
System.out.println("Invalid d of a m:");
fg=false;
}
} //lp y checking
} // checking for vaild date in months
}while(fg==false);
d1="";
d1=d+"/"+m+"/"+y;
for(int i=0;i<n;i++)
        {
        if(students[i].searchByAdmissionDate().equals(d1))
        students[i].displayAll();
        }
       
}
         
        in.close();
    }
    }
class Course
{
Course()
{
seats=new int[3];
seats[0]=0;
seats[1]=0;
seats[2]=0;
}
public String getCourse(String S)
{
for(int i=0;i<3;i++)
if(S.equalsIgnoreCase(course[i]))
{
seats[i]++;
return course[i];
}
return "XX";
}
public int getSeat(String S)
{
for(int i=0;i<3;i++)
{
if(S.equalsIgnoreCase(course[i]))
return seats[i];
}
return -9;
}
public int getSeatLimit(String S)
{
for(int i=0;i<3;i++)
{
if(S.equalsIgnoreCase(course[i]))
return fixSeat[i];
}
return -9;
}
private static String[] course = {"Graduation", "PG", "PhD"};
private static int[] fixSeat={3,2,1};
private int[] seats;
}
class StudentRecord
{

StudentRecord()
{
roll=0;
name="";
co="";
for(int i:marks)
marks[i]=0;
}
public String searchByAdmissionDate()
{
return (dte);
}
public void resultBuild()
{
int sum=0;
System.out.println("Name :"+name);
System.out.println("Course :"+co);
System.out.println("Roll Number :"+roll);
System.out.println("------------------------------------------");
for(int i=0;i<5;i++)
{
System.out.println("Subject "+(i+1)+" "+marks[i]);
sum +=marks[i];
}
System.out.println("Total Marks: "+sum);
System.out.println("Percentage: "+sum/5);
System.out.println("");
}
public void inputData()
{
Scanner in = new Scanner(System.in);
System.out.println("Enter the name:");
name=in.nextLine();
System.out.println("Enter the roll number:");
roll=in.nextInt();
do {
flag=true;
int i=0;
int j=0;
String temp ="";
System.out.println("Enter the admission date(dd/mm/yyyy):");
dte=in.next();
while(dte.charAt(i)!='/' && i<dte.length())
{
if(0 <= dte.charAt(i)-48 && dte.charAt(i)-48 <= 9 )
{
temp=temp+dte.charAt(i);
i++;
j++;
}
else
{
System.out.println("Incorrect format:");
i++;
flag=false;
break;
}
} //day extraction
//System.out.println("Temp="+temp+"I="+i+"J="+j+"flag="+flag);
  if(flag==true && j<=2 && dte.charAt(i)=='/' && j >0 )
{
j=0;
day = Integer.valueOf(temp);
i=i+1;
temp="";
while(dte.charAt(i)!='/' && i<dte.length() )
{
if(0 <= dte.charAt(i)-48 && dte.charAt(i)-48 <= 9 )
{
temp=temp+dte.charAt(i);
i++;
j++;
}
else
{
System.out.println("Incorrect format:");
i++;
//j++;
flag=false;
break;
}
} //month extraction
month = Integer.valueOf(temp);
}
//System.out.println("Temp="+temp+"I="+i+"J="+j+"flag="+flag);

if(flag==true && j<=2 && dte.charAt(i)=='/' && j >0 && month <=12 && 1<=month)
{
j=0;
//month = Integer.valueOf(temp);
//System.out.println(day);
i=i+1;
temp="";
while(i<dte.length())
{
if(0 <= dte.charAt(i)-48 && dte.charAt(i)-48 <= 9 )
{
temp=temp+dte.charAt(i);
i++;
j++;
}
else
{
System.out.println("Incorrect format:");
flag=false;
i++;
break;
//j++;

}
} //year extraction
}
//System.out.println("Temp="+temp+"I="+i+"J="+j+"flag="+flag);
if(flag==true && j==4)
{
year = Integer.valueOf(temp);
flag=true;
}//end of else of year
else
flag=false;
if(flag==true)
{
if(year%400==0)
    leap=true;
else if (year%100==0)
    leap=false;
else if (year%4==0)
    leap=true;
else
    leap=false;
   
if(leap==false)
{
if(day>mdays[month-1] || day < 1 )
{
System.out.println("Invalid day of a month:");
flag=false;
}
}//non-leap year checking
else
{
if(day>ldays[month-1] || day < 1)
{
System.out.println("Invalid day of a month:");
flag=false;
}
} //leap year checking
} // checking for vaild date in months
}while(flag==false);
dte="";
dte=day+"/"+month+"/"+year;
System.out.println("Enter the marks:");
for(int i=0;i<5;i++)
{
System.out.println("Enter the marks in Subject:"+(i+1));
marks[i]=in.nextInt();
}
}
public void setCourse(String S)
{
co=S;
}
public void displayAll()
{
System.out.println("Roll No. = "+roll+" Name= "+name+" Course ="+co);
System.out.println("Admission date: "+dte);
for(int i=0;i<5;i++)
{
System.out.println("Marks in Subject "+(i+1)+"= "+marks[i]);
}
System.out.println("");
}
private int roll;
private String name;
private String co;
private String dte;
private boolean flag=true;
private boolean leap;
private int day;
private int month;
private int year;
int[] marks = new int[5];
int[] mdays={31,28,31,30,31,30,31,31,30,31,30,31};
int[] ldays={31,29,31,30,31,30,31,31,30,31,30,31};
}

Token Identification using Transition diagram

The following program uses transition diagram to identify the pre-defined tokens of C language. For valid token is will display the token type as well as state-table(traversal) and the states at which there is a failure. For invalid tokens it will simply print the states at which it has failed in different transition diagrams: Given below is a part of the transition diagram for pre-defined symbols: The states 34,36,38,40,42 and 44 are final states and will return "{",",",...",?" respectively

Here is the file of complete Transition diagram http://sdrv.ms/1at8wQ3



#include<string.h>
#include<stdlib.h>
#include<stdio.h>
#include<malloc.h>
#define TRUE 1
#define FALSE 0
int main(void)
{
char *str,ar[80];
char *start,*current,*next,*super;
char *ftest[45];
int *fail,iden_final[11],ope_final[7],sym_final[7];
int  count=0,n,len,i=0,key=TRUE,ide_len=0,state=0,choice;
int ide=TRUE,ide_t=TRUE,lit=TRUE,lit_t=TRUE,ope=TRUE,symb=TRUE,numb,negative=FALSE,j=0;
fail=(int *)malloc(44*sizeof(int));
for(i=0;i<45;i++)
{
fail[i]=FALSE;
ftest[i]=(char*)malloc(60*sizeof(char));
}
for(i=0;i<11;i++)
iden_final[i]=FALSE;
for(i=0;i<7;i++)
ope_final[i]=sym_final[i]=FALSE;
printf("\n Enter the maximum length of the statement:");
scanf(" %d", &n);
str=(char *)malloc( (n+1)*sizeof(char));
fflush(stdin);
printf("\n Enter the C statement:");
scanf("%[^\n]",str);
len=strlen(str);
if(len>n)
{
printf("\n Length of the statement is greater than the input length:");
exit(1);
}
super=str;
while(*super==' ')
super++;
while(*super !='\0' || *super =='\n')
{
start=super;
current=start;
next=current;
//Transistion diagram for Keywords int,if,for
switch(*current)
{
case 'i':
  //printf("\n>>>>>>>>%c",*current);
ar[0]=*current;
next +=1;
if(*next == ' ' || *next == '\0')
{
//printf("\n Failed at state 1:");
strcpy(ftest[1],"Failed at state 1:");
fail[1]=TRUE;
//ftest[strlen("Failed at state 1:")]='\0';
key=FALSE;
break;
}
current=next;
if(*current!='n' && *current !='f')
{
//printf("\n Failed at state 1:");
strcpy(ftest[1],"Failed at state 1:");
fail[1]=TRUE;
//ftest[strlen("Failed at state 1:")]='\0';
key=FALSE;
break;
}
ar[1]=*current;
 // printf("\n>>>>>n or f >>>%c",*current);
next +=1;
if(*next == ' ' || *next == '\0' || *current == 'f')
{
//   printf("\n In test loop:");
if(ar[1]!='f')
{
//printf("\n Failed at state 5:");
strcpy(ftest[5],"Failed at state 5:");
fail[5]=TRUE;
//ftest[strlen("Failed at state 5:")]='\0';
key=FALSE;
}
// printf("\n>>>>>>>>>>> [%c]",*next);
if(*next != ' ' && *next!='\0')
{
//printf("\n Failed at state 5:");
key=FALSE;
strcpy(ftest[5],"Failed at state 5:");
fail[5]=TRUE;
 // ftest[strlen("Failed at state 5:")]='\0';
break;
}
ar[2]='\0';
current=next;
if(key==TRUE)
iden_final[6]=TRUE;
printf("%s\t\t Keyword",ar);
break;
}
current=next;
if(*current!='t')
{
//printf("\n Failed at state 2:");
strcpy(ftest[2],"Failed at state 2:");
fail[2]=TRUE;
//ftest[strlen("Failed at state 2:")]='\0';
key=FALSE;
break;
}
ar[2]=*current;
//printf("\n>>>>>>>>%c",*current);
next +=1;
if(*next !=' ' && *next !='\0')
{
//printf("\n Failed at state 3:");
key=FALSE;
strcpy(ftest[3],"Failed at state 3:");
fail[3]=TRUE;
//ftest[strlen("Failed at state 3:")]='\0';
break;
}
current=next;
ar[3]='\0';
//printf("\nFFFFFFFF%c",*current);
iden_final[4]=TRUE;
printf("%s\t\t Keyword",ar);
break;
// CASE for
case 'f':
ar[0]=*current;
next +=1;
if(*next == ' ' || *next == '\0')
{
//printf("\n Failed at state 7:");
strcpy(ftest[7],"Failed at state 7:");
fail[7]=TRUE;
//ftest[strlen("Failed at state 7:")]='\0';
key=FALSE;
break;
}
current=next;
if(*current!='o')
{
//printf("\n Failed at state 7:");
strcpy(ftest[7],"Failed at state 7:");
fail[7]=TRUE;
//ftest[strlen("Failed at state 7:")]='\0';
key=FALSE;
break;
}
ar[1]=*current;
next +=1;
if(*next ==' ' && *next =='\0')
{
//printf("\n Failed at state 8:");
strcpy(ftest[8],"Failed at state 8:");
fail[8]=TRUE;
//ftest[strlen("Failed at state 8:")]='\0';
key=FALSE;
break;
}
current=next;
if(*current!='r')
{
//printf("\n Failed at state 8:");
strcpy(ftest[8],"Failed at state 8:");
fail[8]=TRUE;
//ftest[strlen("Failed at state 8:")]='\0';
key=FALSE;
break;
}
ar[2]=*current;
next +=1;
if(*next !=' ' && *next !='\0')
{
//printf("\n Failed at state 9:");
strcpy(ftest[9],"Failed at state 9:");
fail[9]=TRUE;
//ftest[strlen("Failed at state 9:")]='\0';
key=FALSE;
break;
}
current=next;
ar[3]='\0';
//printf("\nFFFFFFFF%c",*current);
iden_final[10]=TRUE;
printf("%s\t\t Keyword",ar);
break;
default:
//printf("\n Failure at state 0 in Keyword transistion:");
strcpy(ftest[0],"Failed at state 0:");
fail[0]=TRUE;
//ftest[strlen("Failed at state 0:")]='\0';
key=FALSE;
break;
}
// State traversal diagram
if(iden_final[6]==TRUE)
{
printf("\n i\t\t 0(s)---->1");
printf("\n f\t\t 1------->2");
printf("\n *D\t\t 5---->6(f)");
printf("\n");
}
if(iden_final[4]==TRUE)
{
printf("\n i\t\t 0(s)---->1");
printf("\n n\t\t 1------->2");
printf("\n t\t\t 2------->3");
printf("\n *D\t\t 3---->4(f)");
printf("\n");
}
 if(iden_final[10]==TRUE)
{
printf("\n f\t\t 0(s)---->7");
printf("\n 0\t\t 7------->8");
printf("\n r\t\t 8------->9");
printf("\n *D\t\t 9--->10(f)");
printf("\n");
}

// Transistion diagram for identifier
ide_len=0;
i=0;
if(key==FALSE)
{
state=0;
current=start;
while(*current!= ' ' && *current !='\0')
{
ar[i++]=*current;
current++;
}
ar[i]='\0';
current=start;
if( !(65 <= *current && *current <= 93 ) && !(97 <= *current && *current <= 122 )  )
{
//printf("\n Failed at state 11 in identifier transistion:");
strcpy(ftest[11],"Failed at state 11:");
fail[11]=TRUE;
//ftest[strlen("Failed at state 11:")]='\0';
ide_t=FALSE;
ide=FALSE;
}
current +=1;
next=current;
ide_len++;
while(*current!= ' ' && *current !='\0' && ide_t==TRUE)
{
if( (65 <= *current && *current <= 93 ) ||  ( 97 <= *current && *current <= 122)  || ( 48 <= *current && *current <= 57) || *current==95 )
{
ide_len++;
state++;
}
else
{
//printf("\n Failed at state 12:");
strcpy(ftest[1],"Failed at state 12:");
fail[12]=TRUE;
//ftest[strlen("Failed at state 12:")]='\0';
ide_t=FALSE;
ide=FALSE;
break;
}
current++;
}
if(ide_len>8 || ide_t==FALSE )
{ide=FALSE;}//printf("\n %s is Invalid identifier:",ar);
else
{
ide=TRUE;
printf("\n %s\t\t Identifier:",ar);
printf("\n %c\t\t11(s)------->12",ar[0]);
for(i=1;i<=state;i++)
printf("\n %c\t\t12------->12",ar[i]);
printf("\n *D\t\t12------->13");
printf("\n");
}

} // end of trans for iden
// Start of transisition for constant
i=0;
j=0;
state=0;
if(key==FALSE && ide==FALSE)
{
current=start;
while(*current!= ' ' && *current !='\0')
{
ar[i++]=*current;
current++;
}
ar[i]='\0';
current=start;
next=start;
if( !(48 <= *current && *current <= 57 ) )
{
//printf("\n Failed at state 14 in Literal transistion:");
strcpy(ftest[14],"Failed at state 14:");
fail[14]=TRUE;
//ftest[strlen("Failed at state 14:")]='\0';
//addddddd
lit_t=FALSE;
}
if(*current=='-')
negative=TRUE;
current +=1;
next=current;
ide_len++;
while(*current!= ' ' && *current !='\0' && lit_t==TRUE)
{
if((48 <= *current && *current <= 57 ))
{
state++;
}
else
{
//printf("\n Failed at state 15:");
strcpy(ftest[15],"Failed at state 15:");
fail[15]=TRUE;
//ftest[strlen("Failed at state 15:")]='\0';
if(*current!='.')
{
j++;
lit_t=FALSE;
}
else
lit_t=FALSE;
//break;
}
current++;
}
if(lit_t==FALSE )
{
if(negative==TRUE && lit_t==TRUE)
{
printf("\n %s\t\t Out of range:",ar);
lit=TRUE;
}
else
lit=FALSE;
}//printf("\n %s is Invalid identifier:",ar);
else
{
numb=atoi(ar);
if(numb <=0 || numb >999)
{
printf("\n %s\t\t Out of range:",ar);
lit=TRUE;
}
else {
lit=TRUE;
printf("\n %s\t\t Constant:",ar);
printf("\n %c\t\t14(s)------->15",ar[0]);
for(i=1;i<=state;i++)
printf("\n %c\t\t15------->15",ar[i]);
printf("\n *D\t\t15------->16");
printf("\n");

}
}
} // end of if for literal trans
//start of transistion of operators
i=0;
if(key==FALSE && lit==FALSE && ide==FALSE)// && negative == FALSE)
{
//printf("\n in OPERATORSSSSSSSSSSSSSSSSSS");
strcpy(ar,"");
current=start;
next=current;
ar[0]=*current;
//    printf("\n>>>>>>>>> %c",*current);
switch(*current)
{
case '+':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
ope_final[0]=TRUE;
}
else
{
//printf("\n Failed at state 18:");
strcpy(ftest[18],"Failed at state 18:");
fail[18]=TRUE;
//ftest[strlen("Failed at state 18:")]='\0';
ope=FALSE;
}
break;
case '-':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
ope_final[1]=TRUE;
}
else
{
//printf("\n Failed at state 20:");
if((48<= *next && *next <= 57))
{
//printf("\n Failed at state 20:  %c",*next);
strcpy(ftest[20],"Failed at state 20:");
fail[20]=FALSE;
//ftest[strlen("Failed at state 20:")]='\0';
ope=FALSE;
}
else
{
          printf("\n Failed at state 20:  %c",*next);
strcpy(ftest[20],"Failed at state 20:");
fail[20]=TRUE;
//ftest[strlen("Failed at state 20:")]='\0';
ope=FALSE;
}
}
break;
case '*':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
ope_final[2]=TRUE;
}
else
{
//printf("\n Failed at state 22:");
strcpy(ftest[22],"Failed at state 22:");
fail[22]=TRUE;
//ftest[strlen("Failed at state 22:")]='\0';
ope=FALSE;
}
break;
case '/':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
ope_final[3]=TRUE;
}
else
{
//printf("\n Failed at state 24:");
strcpy(ftest[24],"Failed at state 24:");
fail[24]=TRUE;
//ftest[strlen("Failed at state 24:")]='\0';
ope=FALSE;
}
break;
case '=':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
ope_final[4]=TRUE;
}
else
{
//printf("\n Failed at state 26:");
strcpy(ftest[26],"Failed at state 26:");
fail[26]=TRUE;
//ftest[strlen("Failed at state 26:")]='\0';
ope=FALSE;
}
break;
case '>':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
ope_final[5]=TRUE;
}
else
{
//printf("\n Failed at state 28:");
strcpy(ftest[28],"Failed at state 28:");
fail[28]=TRUE;
//ftest[strlen("Failed at state 28:")]='\0';
ope=FALSE;
}
break;
case '<':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
ope_final[6]=TRUE;
}
else
{
//printf("\n Failed at state 30:");
strcpy(ftest[30],"Failed at state 30:");
fail[30]=TRUE;
//ftest[strlen("Failed at state 30:")]='\0';
ope=FALSE;
}
break;
default:
ope=FALSE;
//printf("\n Failed at state 17 in operator transistion:");
strcpy(ftest[17],"Failed at state 17:");
fail[17]=TRUE;
//ftest[strlen("Failed at state 17:")]='\0';
break;
}// end of switch
if(ope==TRUE)
printf("\n %s\t\t Operator",ar);
else
{}//printf("\n %s\t\t is an Invalid Token:",ar);
}     // end of if for operator transisition
// State Table for operators
for(i=0;i<7;i++)
{
if(ope_final[i]==TRUE)
{
printf("\n %s\t\t 17(s)------>%d",ar,18+i*2);
printf("\n *D\t\t %d--------->%d(f)",18+i*2,(18+i*2)+1);
printf("\n");
}
}
// start of transistion for symbols
if(key==FALSE && lit==FALSE && ide==FALSE && ope==FALSE)// && negative == TRUE)
{
//printf("\n in SYMBOLSSSSSSSSSSSSSSSSS");
strcpy(ar,"");
current=start;
next=current;
ar[0]=*current;
//    printf("\n>>>>>>>>> %c",*current);
switch(*current)
{
case '{':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
symb=TRUE;
current=next;
sym_final[0]=TRUE;
}
else
{
//printf("\n Failed at state 33:");
strcpy(ftest[33],"Failed at state 33:");
fail[33]=TRUE;
//ftest[strlen("Failed at state 33:")]='\0';
symb=FALSE;
}
break;
case ',':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
ope=TRUE;
current=next;
sym_final[1]=TRUE;
}
else
{
//printf("\n Failed at state 35:");
strcpy(ftest[35],"Failed at state 35:");
fail[35]=TRUE;
//ftest[strlen("Failed at state 35:")]='\0';
symb=FALSE;
}
break;
case '(':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
symb=TRUE;
current=next;
sym_final[2]=TRUE;
}
else
{
//printf("\n Failed at state 37:");
strcpy(ftest[37],"Failed at state 37:");
fail[37]=TRUE;
//ftest[strlen("Failed at state 37:")]='\0';
symb=FALSE;
}
break;
case ')':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
symb=TRUE;
current=next;
sym_final[3]=TRUE;
}
else
{
//printf("\n Failed at state 39:");
strcpy(ftest[39],"Failed at state 39:");
fail[39]=TRUE;
//ftest[strlen("Failed at state 39:")]='\0';
ope=FALSE;
}
break;
case ';':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
symb=TRUE;
current=next;
sym_final[4]=TRUE;
}
else
{
//printf("\n Failed at state 41:");
strcpy(ftest[41],"Failed at state 41:");
fail[41]=TRUE;
//ftest[strlen("Failed at state 41:")]='\0';
symb=FALSE;
}
break;
case '?':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
symb=TRUE;
current=next;
sym_final[5]=TRUE;
}
else
{
//printf("\n Failed at state 43:");
strcpy(ftest[43],"Failed at state 43:");
fail[43]=TRUE;
//ftest[strlen("Failed at state 43:")]='\0';
symb=FALSE;
}
break;
case '<':
next +=1;
if(*next ==' ' || *next=='\0')
{
ar[1]='\0';
symb=TRUE;
current=next;
sym_final[6]=TRUE;
}
else
{
 // printf("\n Failed at state 30:");
symb=FALSE;
}
break;
default:
symb=FALSE;
//printf("\n Failed at state 32 in operator transistion:");
strcpy(ftest[32],"Failed at state 32:");
fail[32]=TRUE;
//ftest[strlen("Failed at state 32:")]='\0';
break;
}// end of switch
if(symb==TRUE)
printf("\n %s\t\t Symbol",ar);
else
{
if(atof(ar) || ar[0]=='0')
{
if(lit_t==FALSE && j>=1)
printf("\n %s\t\t is an Invalid Identifier:",ar);
else
printf("\n %s\t\t is an Invalid Constant:",ar);
}
else
printf("\n %s\t\t is an Invalid Token:",ar);
}
}              // end of if for symbol transistion
//printf("\ncurrent =[%c]",*current);
// State table for Symbols
for(i=0;i<7;i++)
{
if(sym_final[i]==TRUE)
{
printf("\n %s\t\t 32(s)------>%d",ar,33+i*2);
printf("\n *D\t\t %d--------->%d(f)",33+i*2,(33+i*2)+1);
printf("\n");
}
}
// Display failed states
printf("\n Want to see the failed states in different transistion 1/2:");
scanf("%d",&choice);
switch(choice)
{
case 1:
for(i=0;i<45;i++)
if(fail[i]==TRUE)
printf("\n%s",ftest[i]);
break;
case 2:
default:
break;
}
// variables resetting
for(i=0;i<11;i++)
iden_final[i]=FALSE;
for(i=0;i<7;i++)
ope_final[i]=sym_final[i]=FALSE;
for(i=0;i<45;i++)
fail[i]=FALSE;
key=TRUE;
ide_len=0;
ide=TRUE;
ide_t=TRUE;
lit=TRUE;
lit_t=TRUE;
ope=TRUE;
symb=TRUE;
negative=FALSE;
strcpy(ar,"");
printf("\n");
current=start;
next=current;
//printf("\n current =[%c]",*current);
do
{
if(*current=='\0' || *current=='\n')
break;

 // printf("\n current(loop) =[%c]",*current);
current++;
} while(*current!=' ');
do
{
if(*current=='\0' || *current=='\n')
break;

  // printf("\n current(loop) =[%c]",*current);
current++;
} while(*current==' ');
//printf("\n after current =[%c]",*current);
if(*current=='\0' || *current=='\n')
break;
next=current;
start=current;
super=current;
//printf("\n super =[%c]",*super);
if(*super=='\0' || *super =='\n' || *super ==' ')
break;
} // one token classification
return 0;
}

Newton's Backward Interpolation

#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>
void differenceTable(double **A,double **L,int ROW);
double result(double **A,double **L,double x,int ROW);
double factorial(int n);
FILE *fp;
int main(int argc, char *argv[])
{
double **A,*b,*xn,*xnplus1,*p,temp,x,**L,**U,lambda,error,t1=0.0;
int ROW,i,j,k,t=1,m=1,bo=1;
char ch;
if(argc==1)
{
printf("\n Enter the number of values:");
scanf("%d",&ROW);
printf("\n Enter the value at which value has to be aprroximated:");
scanf("%lf",&x);
A=(double **)malloc((ROW+1)*sizeof(double*));
L=(double **)malloc((ROW+1)*sizeof(double*));
U=(double **)malloc((ROW+1)*sizeof(double*));
for(i=0;i<=ROW;i++)
{
A[i]=(double *)malloc((ROW+1)*sizeof(double));
L[i]=(double *)malloc((ROW+1)*sizeof(double));
U[i]=(double *)malloc((ROW+1)*sizeof(double));
}
b=(double *)malloc((ROW+1)*sizeof(double));
p=(double *)malloc((ROW+1)*sizeof(double));
xn=(double *)malloc((ROW+1)*sizeof(double));
xnplus1=(double *)malloc((ROW+1)*sizeof(double));
for(i=1;i<=ROW;i++)
{
printf("\n Enter the value of X[%d]:",i);
scanf("%lf",&A[i][1]);
}
for(i=1;i<=ROW;i++)
{
printf("\n Enter the value of Y[%d]:",i);
scanf("%lf",&A[i][2]);
}

}
else if (argc==2)
{
fp=fopen(argv[1],"r");
if(fp==NULL)
{
printf("\n File not found, program will terminate:");
exit(0);
}
fscanf(fp,"%d",&ROW);
fscanf(fp,"%lf",&x);
A=(double **)malloc((ROW+1)*sizeof(double*));
L=(double **)malloc((ROW+1)*sizeof(double*));
U=(double **)malloc((ROW+1)*sizeof(double*));
for(i=0;i<=ROW;i++)
{
A[i]=(double *)malloc((ROW+1)*sizeof(double));
L[i]=(double *)malloc((ROW+1)*sizeof(double));
U[i]=(double *)malloc((ROW+1)*sizeof(double));
}
b=(double *)malloc((ROW+1)*sizeof(double));
p=(double *)malloc((ROW+1)*sizeof(double));
xn=(double *)malloc((ROW+1)*sizeof(double));
xnplus1=(double *)malloc((ROW+1)*sizeof(double));

while(!feof(fp))
{
for(i=1;i<=ROW;i++)
{
for(j=1;j<=2;j++)
{
fscanf(fp,"%lf ",&A[i][j]);
}

}
}
fclose(fp);
}
else
{
printf("\n Invalid Arguments,program will terminate:\n");
exit(0);
}
printf("\n         X          Y");
printf("\n------------------------------------------------------------------\n");
for(i=1;i<=ROW;i++)
{
for(j=1;j<=2;j++)
{

U[i][j]=A[i][j];
printf("   %+lf",U[i][j]);
}
printf("\n");
}
for(i=1;i<=ROW-1;i++)
{
for(j=ROW-i,t=1;j>=1;j--,t++)
{
L[t][i]=U[t+1][2]-U[t][2];
}
for(t=1;t<=ROW-i;t++)
U[t][2]=L[t][i];
}
differenceTable(A,L,ROW);
printf("\n Value at %+lf by Newton's Backward Interpolation formula is %+lf\n",x,result(A,L,x,ROW));
return 0;
}
double result(double **A,double **L,double x,int ROW)
{
int i,j,flag=1,t;

double h,value=0,p,tmp=1.0;
h=A[2][1]-A[1][1];
p=(A[ROW][1]-x)/h;
for(i=0,t=ROW+1;i<=ROW;i++,t--)
{
if(i==0)
value +=A[ROW][2];
else
{
for(j=1;j<=i;j++)
tmp=tmp*(p-j+1)*(-1);
tmp = tmp/factorial(i);
tmp = tmp*L[t-1][i];
value +=tmp;
}
tmp=1.0;
}
return value;
}
double factorial(int n)
{
 if(n<=1)
  return 1;
 else
  return n*factorial(n-1);
}
void differenceTable(double **A,double **L,int ROW)
{
int **position,*ap,j,m,i;
position=(int **)malloc((ROW+1)*sizeof(int*));
ap=(int *)malloc((ROW+1)*sizeof(int));
for(i=0;i<=ROW;i++)
position[i]=(int *)malloc((ROW+1)*sizeof(int));
int an,tmp;
tmp=ROW;
for(i=1;i<=ROW;i++)
{
an=1+(i-1)*2;
ap[i]=an;
for(j=1;j<=tmp;j++)
{
position[i][j]=an+(j-1)*4;
}
tmp--;
}
tmp=ROW;
tmp=ROW+(ROW-1)*3;
int *match,tmp1,l,*pos,flag,z,k;
match=(int *)malloc((ROW+1)*sizeof(int));
pos=(int *)malloc((ROW+1)*sizeof(int));
for(i=0;i<=ROW;i++)
{
match[i]=0;
pos[i]=0;
}

printf("\n-----------------------------Difference Table-----------------------------\n");
printf("\n X       Y");
for(i=1;i<=ROW-1;i++)
printf("      D_%d",i);
printf("\n--------------------------------------------------------------------------\n");
for(i=1;i<=tmp;i++)
{
tmp1=ROW;

for(l=1;l<=ROW;l++)
{
flag=0;
for(m=1;m<=tmp1;m++)
{
if(i==position[l][m])
{
flag=1;
match[l]=1;
pos[m]=position[l][m];
break;
}
} //inner for
if(flag==1)
{
for(k=1;k<=ROW;k++)
{
if(match[k]==0)
{
printf("");
}
else
{
if(k==1)
//printf("(%d,%d)+(%d,%d)|%d",(position[l][m]/4)+1,k,(position[l][m]/4)+1,k+1,i);
printf("%+2.2lf\t%+2.2lf",A[(position[l][m]/4)+1][k],A[(position[l][m]/4)+1][k+1]);
else
{
z=(position[l][m]-ap[k])/4+1;
//printf("\t\t(%d,%d)|%d",z,k-1,i);
printf("\t\t%+2.2lf",L[z][k-1]);
}

}
} //end of k-loop

} //end of flag==1

else
{printf(" ");}
tmp1--;
for(k=0;k<=ROW;k++)
{
pos[k]=0;
match[k]=0;
}
}

printf("\n");
}
printf("\n--------------------------------------------------------------------------\n");
}