Programming For Future

class PrimeNo{ public static void main(String ar[]){ int n=50; boolean isPrime=false; for ( int i=3;i<=n;i++){ for ( int j=2;j<i;j++){ if (i%j==0){ isPrime=false; break ; } else isPrime=true; } if (isPrime) System.out.println(i+ " is prime" ); } } }

class Pattern2{ public static void main(String ar[]){ int n=20; for ( int i=1;i<=n;i++){ for ( int j=1;j<=n;j++){ if (i==1||i==n){ System.out.print( " *" ); } else if (j==1||j==n){ System.out.print( " *" ); } else { System.out.print( " " ); } } System.out.println( "" ); } } } /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ...

class Pattern1{ public static void main(String ar[]){ char []chrs={'a','b','c','d','e','f','g','h','i','j','k','l','m'}; for ( int i=0;i<chrs.length;i++){ for ( int j=0;j<2*chrs.length;j++){ if (j<=i||(2*chrs.length-j)<=i+1){ System.out.print(chrs[i]); } else { System.out.print( " " ); } } System.out.println( "" ); } } } /* OUTPUT a a bb bb ccc ccc dddd dddd eeeee eeeee ffffff ffffff ggggggg ggggggg hhhhhhhh hhhhhhhh iiiiiiiii iiiiiiiii jjjjjjjjjj jjjjjjjjjj kkkkkkkkkkk kkkkkkkkkkk llllllllllll llllllllllll mmmmmmmmmmmmmmmmmmmmmmmmmm */

class Q1iPage139{ static int a=20,b=30; public static void main(String ar[]){ int x=test(6,18); System.out.println(x); } static int test( int a, int b){ int gcd=0; int c=(a<b)?a:b; for ( int i=1;i<=c;i++){ if ((a%i==0)&&(b%i==0)){ gcd=i; } } return gcd; } }

//Program to check palindrom of string class Q4ipage154{ public static void main(String ar[]){ boolean b=pal( "nitin" ); System.out.println(b); } static boolean pal(String s) { boolean p=true; int start=0,end=s.length()-1; while (start<end){ if (!(s.charAt(start)==s.charAt(end))){ p=false; break ; } start++; end--; } return p; } }

class Q3apage246{ public static void main(String ar[]){ int n=4; int a[][]= new int [n][]; int c=0; for ( int i=0;i<n;i++){ a[i]= new int [i+1]; for ( int j=0;j<n;j++){ if (j<=i){ a[i][j]=c; c++; } } } for ( int i=0;i<n;i++){ for ( int j=0;j<n;j++){ if (j<=i){ System.out.print(a[i][j]); } } System.out.println( "" ); } } } OUTPUT 0 12 345 6789

class Fib{ static int fib( int a) { if (a==1||a==2) return 1; else { int n=fib(a-1)+fib(a-2); return n; } } public static void main(String ar[]) throws Exception { int a=10,i; for (i=1;i<=a;i++) { System.out.printf( "%5d" ,fib(i)); } } }

/*189=9 * 1+8+9=18 * 1+8=9 (output) */ class Main{ static int rem=0,s=0; static void sum( int num){ s=0; while (num>0){ rem=num%10; num=num/10; s=s+rem; } if (s>=10){ sum(s); } } public static void main(String ar[]){ int d=1891; sum(d); System.out.println( "Single Digit sum =" +s); } }

class Pattern{ public static void main(String ar[]){ int n=5; for(int i=0;i<n;i++){ for(int j=1;j<=(2*n);j++){ int start=n-i; int end=n+i; if((j>=start)&&(j<=(end))){ System.out.print(i+1); } else{ System.out.print(" "); } } System.out.println(""); } } }

class Pattern{ public static void main(String ar[]){ int n=20; for(int i=0;i<n;i++){ for(int j=1;j<=(2*n);j++){ int start=n-i; int end=n+i; if((j>=start)&&(j<=(end))){ System.out.printf("%2d",i+1); } else{ System.out.printf("%2s"," "); } } System.out.println(""); } } }

class Pattern2DArray{ import java.io.*; class Matrix{ static int i=0,j=0; public static void main(String ar[])throws IOException{ int a[][]={{1,2,3},{2,2,2},{1,2,3}}; printArray(a); } public static void printArray(int arr[][]){ if(i>arr.length-1) { return; } else { System.out.print(" "+arr[i][j]); if(i<arr.length && j==arr[i].length-1){ i++; j=0; System.out.println(); printArray(arr); }else{ j++; printArray(arr); } } } }

import java.io.*; class PrintArray{ static int i=0,j=0; public static void main(String ar[])throws IOException{ int a[]={23,23,23,5,45,4,65,6,34,7,56,7,88,78,7,5,45,6,4}; printArray(a); } public static void printArray(int arr[]){ if(i>arr.length-1) { return; } else { System.out.println(" "+arr[i]); i++; printArray(arr); } } }

import java.io.*; class Matrix{ public static void main(String ar[])throws IOException{ int a[][]={{1,2,3},{2,2,2},{1,2,3}}; int b[][]={{1,2,3},{2,2,2},{1,2,3}}; int c[][]=new int[3][3]; /* BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); System.out.println("First Array"); for(int i=0;i

class LCM{ public static void main(String ar[]){ int a=8,b=12; double x=((a*b)/gcd(a,b)); System.out.println("LCM = "+x); } static int gcd(int a,int b) { if (a>=b&&a%b==0) return(b); else if(a<b) return(gcd(b,a)); else return(gcd(b,a%b)); } }

GCD class GCD{ public static void main(String ar[]){ int x=gcd(12,16); System.out.println("gcd = "+x); } static int gcd(int a,int b) { if (a>=b&&a%b==0) return(b); else if(a<b) return(gcd(b,a)); else return(gcd(b,a%b)); } }

class ComplexNumber { int r=0; int i=0; String c; ComplexNumber(int r,int i){ this.r=r; this.i=i; if(i>=0) c=""+r+"+"+i+"i"; else c=""+r+i+"i"; } public String toString(){ return c; } public ComplexNumber add(ComplexNumber c){ int r=this.r+c.r; int i=this.i+c.i; return new ComplexNumber(r,i); } } class Complex{ public static void main(String ar[]) { ComplexNumber c1=new ComplexNumber(2,3); ComplexNumber c2=new ComplexNumber(1,-2); ComplexNumber c3=c1.add(c2); System.out.println(c1); System.out.println(c2); System.out.println(c3); } }