This document contains Java code snippets for various mathematical and logical programs, including programs to: - Add, subtract, multiply, and divide two numbers - Check if a number is even or odd - Find the factorial of a number recursively and using a while loop - Determine if a number is prime - Calculate the roots of a quadratic equation - Convert a binary number to decimal The document provides over 20 code examples of common programming problems and their solutions in Java.

1. Java Program for Addition of two
numbers
importjava.io.*;
importjava.lang.*;
classAddition
{
publicstaticvoidmain(String args[])throwsIOException
{
intn1,n2;
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("enter first number: ");
n1=Integer.parseInt(br.readLine());
System.out.println("enter second number: ");
n2=Integer.parseInt(br.readLine());
n1+=n2;
System.out.println("addition of two numbers is: "+n1);
}
}
Java Program for Subtraction of two
numbers
importjava.io.*;
importjava.lang.*;
classSub
{
publicstaticvoidmain(String args[])throwsIOException
{
intn1,n2;
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter first number: ");
n1=Integer.parseInt(br.readLine());
System.out.println("Enter second number: ");
n2=Integer.parseInt(br.readLine());
n1-=n2;
System.out.println("Subtraction of two given numbers is: "+n1);
}
}

2. Java Program for Multiplication of two
numbers
importjava.io.*;
importjava.lang.*;
classMul
{
publicstaticvoidmain(String args[])throwsIOException
{
intn1=0,n2;
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter first number ");
n1=Integer.parseInt(br.readLine());
System.out.println("Enter second number ");
n2=Integer.parseInt(br.readLine());
n1*=n2; // or n1=n1*n2
System.out.println("Multiplication of two numbers is: "+n1);
}
}

3. Binary To Decimal Conversion
importjava.io.BufferedReader;
importjava.io.IOException;
importjava.io.InputStreamReader;
publicclassBinaryToDecimal
{
publicstaticvoidmain(String args[]) throwsException, IOException
{
intbin;
inti = 0;
intldigit=0;
intdcm=0;
BufferedReaderbr =
newBufferedReader(newInputStreamReader(System.in));
System.out.print("Enter Binary value: ");
bin=Integer.parseInt(br.readLine());
while(bin != 0)
{
ldigit = bin%10; //last digit of binary no
dcm = dcm+ldigit *((int) Math.pow(2,i));
i++;
bin = bin / 10; //removimg last digit from binary no
}
System.out.println("The decimal value for the given binary is:
"+dcm);
}
}
Solving Power Series
importjava.io.*;
classSeries2
{
publicstaticvoidmain(String args[]) throwsIOException
{
intn;
BufferedReaderbr =
newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter n value: ");
n = Integer.parseInt(br.readLine());
if(n>0)
{
floatsum=0;
for(inti=1; i<=n; i++)
sum=sum+(float)(1)/(i*i);
System.out.println("Sum of Series:"+sum);

4. }
else
System.out.println("You Entered the Wrong no.");
}
}
Java Program to Find Frequency
Count of a Word in Given Text
importjava.io.*;
classFrequencyCount
{
publicstaticvoidmain(String args[]) throwsIOException
{
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter the String: ");
String s=br.readLine();
System.out.println("Enter substring: ");
String sub=br.readLine();
intind,count=0;
for(inti=0; i+sub.length()<=s.length(); i++) //i+sub.length() is
used to reduce comparisions
{
ind=s.indexOf(sub,i);
if(ind>=0)
{
count++;
i=ind;
ind=-1;
}
}
System.out.println("Occurence of '"+sub+"' in String is "+count);
}
}
Java Program to Check Given String
is a POLYNDROME or Not

5. importjava.io.*;
importjava.lang.*;
classPolyndrome
{
publicstaticvoidmain(String args[]) throwsIOException
{
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter the String: ");
String s=br.readLine();
String temp=s;
StringBuffersb= newStringBuffer(s);
sb.reverse();
s=sb.toString();
if(s.equals(temp))
System.out.print("String is polyndrome");
else
System.out.println("String is not polyndrome");
}
}
Java Program to Find Factorial of a
Given Number Using Recursion
importjava.io.*;
classFactorial
{
intfact(intn)
{
if(n<=1)
return1;
else
returnn*fact(n-1);
}
}
classRecursionFact
{
publicstaticvoidmain(String args[]) throwsIOException
{
intno;
BufferedReaderbr =
newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter a Number: ");
no = Integer.parseInt(br.readLine());
if(no<0)
{

6. System.out.println("Negative number is not acceptable.");
}
else
{
Factorial f=newFactorial();
System.out.println("Factorial of "+no+" is: "+f.fact(no));
}
}
}
Java Program to Print Series
1,2,9,28,65
importjava.io.*;
classSeries
{
publicstaticvoidmain(String args[]) throwsIOException
{
intn;
BufferedReaderbr =
newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter no.of elements in series: ");
n = Integer.parseInt(br.readLine());
if(n>0)
{
System.out.println("Series:");
for(inti=0; i<n; i++)
{
System.out.println("t"+(int)(Math.pow(i,3)+1)); //Pattern
for elements
}
}
else
System.out.println("You Entered the Wrong no.");
}
}
Java Program to Print Prime Numbers
With Less Comparisons
importjava.io.*;

7. importjava.lang.*;
classPrime
{
publicstaticvoidmain(String args[]) throwsIOException
{
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter the value: ");
intn=Integer.parseInt(br.readLine());
System.out.println("Prime numbers are: ");
for(inti=1; i<=n; i++)
{
intnf=0;
for(intj=1; j<=(i/2); j++) //( i/2) reduces no.ofcomparisions
{
if(i%j==0)
nf++;
}
if(nf==1)
System.out.print(" "+i);
}
}
}
Java Program to Find Roots of a
Quadratic Equation
importjava.io.*;
classQuad
{
publicstaticvoidmain(String args[]) throwsIOException
{
inta,b,c;
BufferedReaderbr =
newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter a,b,c values: ");
a= Integer.parseInt(br.readLine());
b= Integer.parseInt(br.readLine());
c= Integer.parseInt(br.readLine());
if((a==0)&&(b==0)&&(c==0))
{
System.out.println("Enter atleast two non-zero co-efficients");
}
else
{
floatr1=0,r2=0;
if(a==0)
{
r1= (float)-c/b;
System.out.println("The roots are:"+r1);
}
else

8. {
floatd=(b*b)-(4*a*c);
if(d<0)
{
System.out.println("Roots are imaginary");
floatreal=(float)(-b)/(2*a);
floatimg=(float)(Math.sqrt(Math.abs(d)))/(2*a);
System.out.println("r1="+real+"+i"+img);
System.out.println("r2="+real+"-i"+img);
}
else
{
r1=(float)(-b+Math.sqrt(d))/(2*a);
r2=(float)(-b-Math.sqrt(d))/(2*a);
if(d==0)
{
System.out.println("Roots are real and equal");
}
else
{
System.out.println("Roots are real and different");
}
System.out.println("r1="+r1);
System.out.println("r2="+r2);
}
}
}
}
}
Java Program to Print Square Series
0,1,4,9,16
importjava.io.*;
classSquareSeries
{
publicstaticvoidmain(String args[]) throwsIOException
{
intn;
BufferedReaderbr =
newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter no.of elements in series: ");
n = Integer.parseInt(br.readLine());
if(n>0)
{
System.out.println("Series:");
for(inti=0; i<(n-1); i++)
{

9. System.out.println("t"+(int)(Math.pow(i,2)));
}
}
else
System.out.println("You Entered the Wrong no.");
}
}
Java Program to Find Given Number
Is Even or Odd
importjava.io.*;
importjava.lang.*;
classEvenOdd
{
publicstaticvoidmain(String args[])throwsIOException
{
intn=0;
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter number: ");
n=Integer.parseInt(br.readLine());
n=n%2;
if(n==0)
System.out.println("The given number is even ");
else
System.out.println("The given number is odd ");
}
}
Java Program for Multiplication of two
numbers
importjava.io.*;
importjava.lang.*;
classMul
{
publicstaticvoidmain(String args[])throwsIOException
{
intn1=0,n2;
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter first number ");
n1=Integer.parseInt(br.readLine());
System.out.println("Enter second number ");
n2=Integer.parseInt(br.readLine());
n1*=n2; // or n1=n1*n2

10. System.out.println("Multiplication of two numbers is: "+n1);
}
}
Java Program for Division of Two
Numbers
importjava.io.*;
importjava.lang.*;
classDiv
{
publicstaticvoidmain(String args[])throwsIOException
{
intn1=0,n2;
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter first number: ");
n1=Integer.parseInt(br.readLine());
System.out.println("Enter second number: ");
n2=Integer.parseInt(br.readLine());
n1/=n2;
System.out.println("Division of two numbers is: "+n1);
}
}
Java Program for Addition of Two
Static Integer Numbers
importjava.io.*;
importjava.lang.*;
classStaticAdd
{
publicstaticvoidmain(String args[])
{
intn1=10,n2=20; //Static Defining of two Integer Variables
n1+=n2; // Performing Addition
System.out.println("Addition: "+n1);
}
}
Java Program for Multiplication of
Two Static Numbers
importjava.io.*;
importjava.lang.*;
classStaticMul

11. {
publicstaticvoidmain(String args[])
{
intn1=20,n2=10; //Defining Static Integer values
n1*=n2; // or n1=n1*n2;
System.out.println("Multiplicatation : "+n1);
}
}
Java Program to find Given Number is
Prime or Not
/* Write a Java program to Find whether number is Prime or Not. */
classPrimeNumber
{
publicstaticvoidmain(String args[])
{
intnumber = Integer.parseInt(args[0]);
intflag=0;
for(inti=2; i<number; i++)
{
if(number%i==0)
{
System.out.println(number+" is not a Prime Number");
flag = 1;
break;
}
}
if(flag==0)
System.out.println(number+" is a Prime Number");
}
}
Java Program to Find Whether Given
number is Armstrong or not
/*Write a program to find whether given no. is Armstrong or not.
Example :
Input - 153
Output - 1^3 + 5^3 + 3^3 = 153, so it is Armstrong no. */
classArmstrong
{
publicstaticvoidmain(String args[])
{<br> //Read Command Line Argument
intnum = Integer.parseInt(args[0]);
intn = num; //use to compare at If stmt
intcheck=0,remainder;

12. while(num> 0)
{
remainder = num % 10;
check = check + (int)Math.pow(remainder,3);
num = num / 10;
}
if(check == n)
System.out.println(n+" is an Armstrong Number");
else
System.out.println(n+" is not a Armstrong Number");
}
}
Java Program to Find Factorial of a
Given Number using While Loop
importjava.io.*;
importjava.lang.*;
classFactorial
{
publicstaticvoidmain(String args[]) throwsIOException
{
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter Number: ");
intnum=Integer.parseInt(br.readLine());
intresult = 1;
while(num>0)
{
result = result * num;
num--;
}
System.out.println("Factorial of Given Number is : "+result);
}
}
Java Program to Find Maximum of
Two Numbers
classMaxoftwo
{
publicstaticvoidmain(String args[])
{
//taking value as command line argument.
//Converting String format to Integer value

13. inti = Integer.parseInt(args[0]);
intj = Integer.parseInt(args[1]);
if(i> j)
System.out.println(i+" is greater than "+j);
else
System.out.println(j+" is greater than "+i);
}
}
Java Program to Print Prime Numbers
up to Given Number
importjava.io.*;
importjava.lang.*;
classPrime
{
publicstaticvoidmain(String args[]) throwsIOException
{
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));
System.out.println("Enter the value: ");
intn=Integer.parseInt(br.readLine());
System.out.println("Prime numbers are: ");
for(inti=1;i<=n;i++)
{
intp=0;
for(intj=1;j<=i;j++)
{
if(i%j==0)
p++;
}
if(p==2)
System.out.print(" "+i);
}
}
}
Java Program for Fibonacci Series
importjava.io.*;
importjava.lang.*;
classFibonacci
{
publicstaticvoidmain(String args[]) throwsIOException
{
BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));

14. System.out.println("Enter the value:");
intn=Integer.parseInt(br.readLine());
intt1=0,t2=1;
System.out.print("Fibonacci Series is "+t1+" "+t2);
for(inti=0; i<n; i++)
{
intt3=t1+t2;
t1=t2;
t2=t3;
System.out.print(" "+t3);
}
}
}