Java Programs Library

contains words starting with 'c' and ending with 'i'

contains words starting with 'c' and ending with 'i'

Formula based java code

public class Addition {
//Formula based
public static void main(String[] args) {
// 5+55+555 = 615
// 5(1+11+111) = 615
// Formula n(1+11+111)

String value="5+55+555";
String[] splitValue=value.split("\\+");
int n=Integer.parseInt(splitValue[0]);
int total = n*(1+11+111);
System.out.println(total);
}
}

Finding missing Number ::-

import java.util.Arrays;

public class MissingNumber {


public static void main(String[] args) {

int[] numbers={1,2,3,4,5,6,8,9}; // 7 is missing
int n=numbers.length+1; // 8+1=9
int idealSum=(n*(n+1)) /2; // (9(9+1))/2=45
int sum=Arrays.stream(numbers).sum();// sum=38
int value=idealSum - sum; // 45-38=7
System.out.println(value); //7
}
}

Insertion Sorting using Array

public class InsertionSort {

public static int[] a=new int[10];
static int currentSize=0;
public static void main(String[] args) {

ins(a,7); ins(a,3); ins(a,8);
ins(a,5); ins(a,4); ins(a,2);
ins(a,1); ins(a,4); ins(a,6); ins(a,4);

System.out.println(java.util.Arrays.toString(a));
}


public static void ins(int[] arr, int value){
if(currentSize==0){
arr[currentSize++]=value;
} else {
int i;
//for (i=currentSize-1; (i >= 0 && arr[i] < value); i--) // Descending Order
for (i=currentSize-1; (i >= 0 && arr[i] > value); i--) // Ascending Order
arr[i+1] = arr[i];

arr[i+1] = value;
currentSize++;
}
}
}

A number is a Spy number, if sum and product of all digits are equal.
* In this java program, we are going to check whether a given number is SPY number or not?
* Example input = 123;
* sum = 1+2+3=6;
* mult=1*2*3=6;
* if(sum==mult) { "Spy Number" } else { "Not Spy Number" }

public class Spy {

public static void main(String[] args) {

int no, pro, sum, digit;
pro = 1;
sum = 0;
no = 123;

while(no != 0) {
digit = no % 10;
pro = pro * digit;
sum = sum + digit;
no = no / 10;
}

if(sum == pro)
System.out.println("Spy Number");
else
System.out.println("Not Spy Number");

}
}

Sort on a string that may contain a number with plus

import java.util.Arrays;
import java.util.Collections;

public class StringNumberSort {
public static void main(String[] args) {
String data = "2+9+5+4+7+1+7";
String[] numbers = data.split("\\+");

Integer[] intValues = new Integer[numbers.length];
for (int i = 0; i < numbers.length; i++) {
intValues[i] = Integer.parseInt(numbers[i].trim());
}

Collections.sort(Arrays.asList(intValues));

StringBuilder builder = new StringBuilder();
for (int i = 0; i < intValues.length; i++) {
Integer intValue = intValues[i];
builder.append(intValue);
if (i < intValues.length - 1) {
builder.append("+");
}
}
System.out.println("Before = " + data);
System.out.println("After = " + builder.toString());
}
}

print Amstrong Number1 to 1000

package com.test;

public class AmstrongNumber {

public static void main(String[] args) {
for (int i = 1; i

print PerfectNumber 1 to 1000

public class PerfectNumber {

public static void main(String[] args) {
for (int i =1; i < 1000; i++) {
isPerfectNumber(i);
}
}


public static void isPerfectNumber(int number) {

int temp=0;

for (int i=1; i

Convert int to binary

public class {

public static void convertBinary(int num){
int binary[] = new int[40];
int index = 0;
while(num > 0) {
binary[index++] = num%2;
num = num/2;
}

for(int i = index-1;i >= 0;i--) {
System.out.print(binary[i]);
}
}


public static void main(String[] args) {
convertBinary(45);
}

}

Below example shows how to convert string format of a number to number without calling Integer.parseInt() method. We can do this by converting each character into ascii format and form the number.

public class StringToNumber {

public static int convert_String_To_Number(String num){

char[] ch=num.toCharArray();
int sum=0;
int zeroAscii=(int) '0';

for(char c:ch) {
int tempAscii=(int) c;
sum=(sum*10)+(tempAscii-zeroAscii);
}

return sum;
}



public static void main(String[] args) {
System.out.println("\"3256\" == "+convert_String_To_Number("3256"));
System.out.println("\"76289\" == "+convert_String_To_Number("76289"));
System.out.println("\"90087\" == "+convert_String_To_Number("90087"));
}
}

// i/p : 1 2 3 4 5 6 7 8
// o/p : 1 8 2 7 3 6 4 5

public class TestCase {

// i/p : 1 2 3 4 5 6 7 8
// o/p : 1 8 2 7 3 6 4 5

public static void main(String[] args) {
int[] ip={1,2,3,4,5,6,7,8};

int n=ip.length;

int small=0;
int large=n-1;

int tem[]=new int[n];

boolean flag=true;

for (int i = 0; i