public class A {
public static int retrieveDecimal(int binarynumber) {
int decimalnumber = 0;
int power = 0;
while (true) {
if (binarynumber == 0) {
break;
} else {
int temp = binarynumber % 10;
decimalnumber += temp * Math.pow(2, power);
binarynumber = binarynumber / 10;
power++;
}
}
return decimalnumber;
}
public static void main(String args[]) {
System.out.println("Decimal value is: " + retrieveDecimal(1110));
System.out.println("Decimal value is: " + retrieveDecimal(0010));
System.out.println("Decimal value is: " + retrieveDecimal(1010));
System.out.println("Decimal value is: " + retrieveDecimal(0110));
System.out.println("Decimal value is: " + retrieveDecimal(1101));
}
}
class GFG
{
// function to convert decimal to binary
static void decToBinary(int n)
{
// array to store binary number
int[] binaryNum = new int[1000];
// counter for binary array
int i = 0;
while (n > 0)
{
// storing remainder in binary array
binaryNum[i] = n % 2;
n = n / 2;
i++;
}
// printing binary array in reverse order
for (int j = i - 1; j >= 0; j--)
System.out.print(binaryNum[j]);
}
// driver program
public static void main (String[] args)
{
int n = 17;
System.out.println("Decimal - " + n);
System.out.print("Binary - ");
decToBinary(n);
}
}
Example: 371 = 33 + 73 + 13
import java.util.*;
public class Armstrong {
public static void main() {
Scanner sc = new Scanner(System.in);
System.out.println("Enter a number");
int num = sc.nextInt();
String num2 = num + "";
int nod = num2.length();
int number, digit, sum = 0;
number = num;
while (number != 0) {
digit = number % 10;
sum = sum + Math.pow(digit, nod);
number /= 10;
}
if (sum == num)
System.out.println(num + " is an Armstrong number");
else
System.out.println(num + " is not an Armstrong number");
}
}
Example:
Array ar[ ] = 3, 6, 9, 5, 12, 14, 8, 18, 7, 21, 10, 4
Output : Array br[ ] = 6, 12, 14, 8, 18, 10, 4, 21, 7, 5, 9, 3
public class MyClass {
public static void main(String args[]) {
int a[] = {3, 6, 9, 5, 12, 14, 8, 18, 7, 21, 10, 4 };
int len = a.length;
int b[] = new int[len];
int k=0, p=len-1;
System.out.println("Original Array: ");
displayArray(a);
for(int i = 0; i<len; i++)
{
int key = a[i];
if(key % 2 == 0)
{
b[k] = key;
k++;
}
else
{
b[p] = key;
p--;
}
}
System.out.println("\n\nNew Array: ");
displayArray(b);
}
static void displayArray(int a[])
{
for(int i=0; i < a.length; i++)
System.out.print(a[i] + "\t");
}
}
import java.util.Scanner;
public class MyClass {
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
int a[][] = new int[4][5];
System.out.println("Enter elements of the 2d array: ");
int sum = 0, max = Integer.MIN_VALUE, min = Integer.MAX_VALUE;
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 5; j++) {
a[i][j] = sc.nextInt();
int key = a[i][j];
sum += key;
if (key > max)
max = key;
if (key < min)
min = key;
}
}
double avg = sum / 20;
System.out.println("You have enterd: ");
displayArray(a);
System.out.println("Max Number: " + max);
System.out.println("Min Number: " + min);
System.out.println("Average: " + avg);
}
static void displayArray(int a[][]) {
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 5; j++) {
System.out.print(a[i][j] + "\t");
}
System.out.println();
}
}
}
public class MyClass {
public static void main(String args[]) {
String s = "Today is a good day good", word = "";
s += " ";
s = s.toUpperCase();
int count = 0;
for (int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
if (ch != ' ')
word += ch;
else {
if (word.equals("GOOD"))
count++;
word = "";
}
}
System.out.println(count);
}
}
Example :
Input : ZEBRAS ARE FOUND IN THE FOREST
Output: AFCSBT BSF GPVOE JO UIF GPSFTU
public class MyClass {
public static void main(String args[]) {
String s = "Today is a go^od $day good", word = "";
s += " ";
s = s.toUpperCase();
System.out.println(s);
for (int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
if (Character.isLetter(ch)) {
if (ch == 'Z')
ch = 'A';
else
ch++;
}
System.out.print(ch);
}
}
}
import java.util.Scanner;
public class MyClass {
public static void main(String args[]) {
int a[] = new int[20];
Scanner sc = new Scanner(System.in);
System.out.println("Enter 20 elements of the array: ");
for (int i = 0; i < 20; ++i)
a[i] = sc.nextInt();
System.out.println("Before Sorting ");
printArray(a);
getNumbers(a);
System.out.println("After Sorting ");
printArray(a);
}
static void getNumbers(int arr[]) {
int n = arr.length;
for (int i = 0; i < n - 1; i++)
for (int j = 0; j < n - i - 1; j++)
if (arr[j] > arr[j + 1]) {
// swap temp and arr[i]
int temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
/* Prints the array */
static void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
}
import java.util.Scanner;
public class MyClass {
public static void main(String args[]) {
System.out.println("Enter a number");
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int b[] = printFreq(n);
for (int i = 0; i < b.length; i++)
if (b[i] != 0)
System.out.println(i + " " + b[i]);
}
static int[] printFreq(int n) {
int a[] = new int[10];
while (n > 0) {
int d = n % 10;
switch (d) {
case 1:
a[1]++;
break;
case 2:
a[2]++;
break;
case 3:
a[3]++;
break;
case 4:
a[4]++;
break;
case 5:
a[5]++;
break;
case 6:
a[6]++;
break;
case 7:
a[7]++;
break;
case 8:
a[8]++;
break;
case 9:
a[9]++;
break;
case 0:
a[0]++;
break;
}
n = n / 10;
}
return a;
}
}
Distance 1 = 10 feets 24 inches
Distance 2 = 5 feets 16 inches
Sum of distances = 18 feets 4 inches
A class Distance has following members :
Instance variable/data members : f1, f2 (integers to store two feet values)
n1, in2 (integers to store two inches).
Member function/methods :
(i) public Distance(int f, int n1, int ff, int n2)- constructor to initialize f to f1,i n1 to in1, ff to f2, n2 to in2.
(ii) public void showdistance( ) - to display both the distances with suitable message.
(iii) public void Sum0fDistance( ) - to find sum of distances
class Distance {
int f1,f2,in1,in2;
int totalFeet, totalInches;
Distance(int f, int n1, int ff, int n2)
{
f1 = f;
in1 = n1;
f2 = ff;
in2 = n2;
}
public void showDistance() {
System.out.println("Distance 1: " + f1 + " feet " + in1 + " inches");
System.out.println("Distance 2: " + f2 + " feet " + in2 + " inches");
System.out.println("Total Feet: " + totalFeet + "\tTotal Inches: " + totalInches);
}
public void SumOfDistance() {
totalFeet = f1 + f2;
totalInches = in1 + in2;
}
public static void main() {
Distance D1 = new Distance(12,5,14,6);
D1.SumOfDistance();
D1.showDistance();
}
}
(i) Input the limit of series N. Print Fibonacci numbers upto N terms using do-while loop. At the end print sum of all Fibonacci numbers upto N. The Fibonacci numbers are generated by assigning two numbers as 0 and 1 then every third number is sum of two previous numbers. Example: Input N = 7 Output: 0, 1, 1, 2, 3, 5, 8 Sum of all the terms = 20
(ii) Print the following series upto 6 terms. Example: 1, 11, 111, 1111, 11111, 111111
import java.util.Scanner;
class A
{
static void main()
{
Scanner sc = new Scanner(System.in);
System.out.println("--Menu--");
System.out.println("1. Fibonacci");
System.out.println("2. Pattern2");
int choice = sc.nextInt();
switch(choice)
{
case 1: System.out.printn("Enter value of n");
int n = sc.nextInt();
int a = 0, b = 1, sum=a+b, count=2;
System.out.print(a + " " + b);
do
{
System.out.print(" " + c);
a=b;
b=c;
c=a+b;
}while(count<n)
break;
case 2: int p = 0;
for(int i=0; i<6; i++)
{
p = p * 10 + 1;
System.out.print(p);
}
break;
default: System.out.println("Wrong choice");
}
}
}
(i) Prime-Palindrome number: If a number is prime and reads same in reverse and forward, the number is a Prime- Palindrome.
(ii) Armstrong number
import java.util.Scanner;
class A
{
static void main()
{
Scanner sc = new Scanner(System.in);
System.out.println("--Menu--");
System.out.println("1. Prime Palindrome");
System.out.println("2. Armstrong No");
int choice = sc.nextInt();
switch(choice)
{
case 1: System.out.println("Enter a number");
int n = sc.nextInt();
int count=0;
for(int i = 1; i<=n; i++)
{
if(n % i == 0)
count++;
}
int t = n, rev=0;
while(t>0)
{
int d = t%10;
rev=rev*10+d;
t=t/10;
}
if(count==2 && rev==n)
System.out.println(n + " is a Prime Palindrome No");
else
System.out.println(n + " is not a Prime Palindrome No");
break;
case 2: System.out.println("Enter a number");
int m = sc.nextInt();
int p = m, nod=0, sum=0;
while(p>0)
{
nod++;
p=p/10;
}
p = m;
while(p>0)
{
int d = p%10;
sum += Math.pow(d, nod);
p/=10;
}
if(sum == m)
System.out.println(m + " is an armstrong no");
else
System.out.println(m + " is not an armstrong no");
break;
default: System.out.println("Invalid input");
}
}
}
import java.util.*;
class Triangle
{
public static void main( )
{
Scanner sc = new Scanner(System.in);
System.out.println("Enter 3 sides of triangle ");
double s1 = sc.nextDouble( );
double s2 = sc.nextDouble( );
double s3 = sc.nextDouble( );
char ch ='0';
double sq1 = s1 * s1;
double sq2 = s2 * s2;
double sq3 = s3 * s3;
double sum1 = sq1 + sq2;
double sum2 = sq2 + sq3;
double sum3 = sq1 + sq3;
if(s1 == s2 && s2 == s3 )
ch = 'E';
if(s1 == s2 || s2 == s3 || s1 == s3)
ch = 'I';
if(sum1 == sq3 || sum2 == sq1 || sum3 == sq2)
ch = 'R';
if(s1 != s2 && s2!=s3)
ch = 'S';
switch(ch)
{
case 'E': System.out.println("Equilateral triangle"); break;
case 'T': System.out.println("lsoscless triangle"); break;
case 'R': System.out.println("Right triangle"); break;
case 'S': System.out.println("Scalene triangle"); break;
}
}
}
public class A {
// Function to concatenate
// two integers into one
static int concat(int a, int b)
{
// Convert both the integers to string
String s1 = a + "";
String s2 = b + "";
// Concatenate both strings
String s = s1 + s2;
// Convert the concatenated string
// to integer
int c = Integer.parseInt(s);
// return the formed integer
return c;
}
public static void main()
{
int a = 23;
int b = 43;
System.out.println(concat(a, b));
}
}
For example : (3,5) (5,7) (11,13)(17,19) etc.
Write a program to print all twin prime numbers between 3 to 300.
import java.util.Scanner;
public class TwinPrime
{
public static void main(String[] args)
{
int a, b;
Scanner sc = new Scanner(System.in);
System.out.print("Enter a=");
a = sc.nextInt();
System.out.print("Enter b=");
b = sc.nextInt();
if (prime(a) && prime(b) && (Math.abs(a - b) == 2))
{
System.out.println("Twin Prime");
}
else
{
System.out.println("Not Twin Prime");
}
}
static boolean prime(int n)
{
int i = 2;
boolean flag = true;
while (n > i)
{
if (n % 2 == 0)
{
flag = false;
break;
}
i++;
}
return flag;
}
}
Example 1:
Input: s = "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.
Example 2:
Input: s = "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.
public class A {
public int lengthOfLongestSubstring(String s) {
int n = s.length(), ans = 0;
Map<Character, Integer> map = new HashMap<>(); // current index of character
// try to extend the range [i, j]
for (int j = 0, i = 0; j < n; j++) {
if (map.containsKey(s.charAt(j))) {
i = Math.max(map.get(s.charAt(j)), i);
}
ans = Math.max(ans, j - i + 1);
map.put(s.charAt(j), j + 1);
}
return ans;
}
}
import java.util.Scanner;
public class Example {
private static Scanner sc;
public static void main(String[] args) {
sc = new Scanner(System.in);
System.out.println("Enter First and Second Numbers = ");
long b1 = sc.nextLong();
long b2 = sc.nextLong();
int i = 0, carry = 0;
int[] sum = new int[10];
while(b1 != 0 || b2 != 0)
{
sum[i++] = (int)((b1 % 10 + b2 % 10 + carry) % 2);
carry = (int)((b1 % 10 + b2 % 10 + carry) / 2);
b1 /= 10;
b2 /= 10;
}
if(carry != 0)
{
sum[i++] = carry;
}
--i;
System.out.print("\nThe Total of the above Two = ");
while(i >= 0)
{
System.out.print(sum[i--]);
}
System.out.println();
}
}
import java.util.Scanner;
public class A{
public static void main(String args[]){
int temp1, temp2, num1, num2, temp, hcf, lcm;
Scanner scanner = new Scanner(System.in);
System.out.print("Enter First Number: ");
num1 = scanner.nextInt();
System.out.print("Enter Second Number: ");
num2 = scanner.nextInt();
scanner.close();
temp1 = num1;
temp2 = num2;
while(temp2 != 0){
temp = temp2;
temp2 = temp1%temp2;
temp1 = temp;
}
hcf = temp1;
lcm = (num1*num2)/hcf;
System.out.println("HCF of input numbers: "+hcf);
System.out.println("LCM of input numbers: "+lcm);
}
}
Sample Output:
Original String = Java Exercises!
The character at position 0 is J
The character at position 10 is i
import java.util.Scanner;
public class A
{
public static void main()
{
Scanner sc = new Scanner(System.in);
System.out.println("Enter a string ");
String str = sc.nextLine();
System.out.println("\nOriginal String = " + str);
System.out.println("\nChoose an index between 0 and " + (str.length()-1));
int index=sc.nextInt();
System.out.println("\nThe character at position " + index + " is " + str.charAt(index));
}
}
Sample Input: and
Original String: Java Exercises and Python Exercises
Specified sequence of char values: and
true
public class A {
public static void main(String[] args)
{
String str1 = "This is a test of reality";
String str2 = "est";
System.out.println("Original String: " + str1);
System.out.println("Specified sequence of char values: " + str2);
System.out.println(str1.contains(str2));
}
}
Project:
//Program Author: Rishikesh Sahani"
import java.io.*;
import java.util.Scanner;
public class Movie
{
int choice, noOfAvailableSeats;
Scanner sc;
public static void main()
{
Movie obj = new Movie();
do
{
obj.displayMenu();
obj.getChoice();
switch(obj.choice)
{
case 1: obj.bookTicket();
break;
case 2: obj.cancelTicket();
break;
case 3: obj.showAvailable(true);
break;
case 4: obj.resetSeats();
break;
case 5: System.out.println("\n*****Program Terminated*****");
System.exit(0);
default: System.out.println("Invalid Choice!! Try Again!!");
}
}while(obj.choice != 5);
}
void getChoice()
{
System.out.print("\n\nPlease enter your choice: ");
sc = new Scanner (System.in);
choice = sc.nextInt();
sc.close();
}
void displayMenu()
{
System.out.println("\n\n\n\n---Movie Ticket Booker---");
System.out.println("--------------------------");
System.out.println("| 1.Book a ticket |");
System.out.println("| 2.Cancel a ticket |");
System.out.println("| 3.Check Availability |");
System.out.println("| 4.Reset Seats |"); //cancel all tickets
System.out.println("| 5.Exit |");
System.out.println("--------------------------");
}
void showAvailable(boolean printSeats)
{
try
{
File myObj = new File("d:\\movie.txt");
Scanner myReader = new Scanner(myObj);
while (myReader.hasNextInt())
{
String data = myReader.nextLine();
noOfAvailableSeats = Integer.valueOf(data);
System.out.println("\nTotal Seats Available: " + noOfAvailableSeats);
}
myReader.close();
if(printSeats)
printSeats();
}
catch (FileNotFoundException e)
{
System.out.println("An error occurred.");
e.printStackTrace();
}
}
void printSeats()
{
int count=0;
System.out.println();
for(int i=1;i<=noOfAvailableSeats; i++)
{
System.out.print("\u2b1b\t");
count++;
if(count == 10)
{
System.out.println("\n");
count=0;
}
}
}
void cancelTicket()
{
showAvailable(true); //read/update number of seats available in noOfAvailableSeats variable
sc = new Scanner(System.in);
System.out.print("\n\nEnter how many tickets to cancel: ");
int not = sc.nextInt(); //no of tickets need to be cancelled
sc.close();
if(not + noOfAvailableSeats > 100)
{
System.out.println("Tickets not cancelled. Maximum Tickets that can be cancelled is: " + (100 - noOfAvailableSeats));
}
else
{
noOfAvailableSeats += not;
try
{
FileWriter myWriter = new FileWriter("d:\\movie.txt");
myWriter.write(noOfAvailableSeats+"");
myWriter.close();
System.out.println(not + " tickets successfully cancelled!!\n\n");
printSeats();
}
catch (IOException e)
{
System.out.println("An error occurred.");
e.printStackTrace();
}
}
}
void bookTicket()
{
showAvailable(true); //read/update number of seats available in noOfAvailableSeats variable
if(noOfAvailableSeats == 0)
{
System.out.println("\nAll tickets booked out. Sorry!!\n");
return;
}
sc = new Scanner(System.in);
System.out.print("\n\nEnter how many tickets: ");
int not = sc.nextInt(); //no of tickets need to be booked
sc.close();
if(not <= noOfAvailableSeats) //no of tickets needed should be less than available seats
{
noOfAvailableSeats = noOfAvailableSeats - not;
try
{
FileWriter myWriter = new FileWriter("d:\\movie.txt");
myWriter.write(noOfAvailableSeats+"");
myWriter.close();
System.out.println(not + " tickets successfully booked!! Enjoy the movie!!\n\n");
printSeats();
}
catch (IOException e)
{
System.out.println("An error occurred.");
e.printStackTrace();
}
}
else
{
System.out.println("\nNo. of tickets should be less than " + noOfAvailableSeats);
printSeats();
}
}
void resetSeats()
{
try
{
FileWriter myWriter = new FileWriter("d:\\movie.txt");
myWriter.write("100");
myWriter.close();
System.out.println("Reset complete!");
}
catch (IOException e)
{
System.out.println("An error occurred.");
e.printStackTrace();
}
}
}