Binary Search in java

Time Complexity for Binary Search will be Log(n).  But the main Condition is, the inputted elements in the array must be sorted (ascending order).



import java.util.*;

class BSearch
{
  public static void main(String[] args)
  {
  Scanner s=new Scanner(System.in);
  int n=s.nextInt();
  int a[]=new int[n];
 
  for(int i=0;i<n;i++)
 a[i]=s.nextInt();
 
  System.out.println("enter the element to be find");
  int f=s.nextInt();
 
  int k=bs(a,0,n-1,f);
  if(k==-1)
 System.out.println("the element not present");
  else
      System.out.println("the element is at index  "+(k+1));
  }
 
 
  static int bs(int a[],int st,int en,int f)
  {
 if(en>=st)
 {
  int mid=(st+en)/2;

  if(a[mid]==f)
 return mid;
  else if(a[mid]<f)
 return bs(a,mid+1,en,f);
  else
 return bs(a,0,mid-1,f);
 }

 return -1;
  }
}

Single Link List in java

import java.util.*;

class Intnode
{
  public int data;
  public Intnode next;
 
  Intnode()
  {
  this.next=null;
  }
}



public class Linklist
{
  public static void main(String[] args)
  {
   Scanner s = new Scanner(System.in);
   Intnode start= new Intnode();
   Intnode temp=start;
 
    System.out.println("Please enter data in the node");
    int k=s.nextInt();
start.data=k;

while(true)
{
 System.out.println("do u want to make more such node ? press y/n");
  char a= s.next().charAt(0);
 
  if(a=='n')
   break;

  Intnode temp2= new Intnode();
  System.out.println("Please enter data in the node");
       k=s.nextInt();
  temp2.data=k;
 
temp.next=temp2;
temp=temp.next;
}

temp =start;
while(temp!=null)
{
 System.out.print(temp.data+" ->");
 temp=temp.next;
}

  }

}

Quick Sort in java

import java.util.*;

class qsort
{

 public static void main(String args[])
 {
Scanner s=new Scanner(System.in);
int n=s.nextInt();

int a[]=new int [n];

for(int i=0;i<n;i++)
a[i]=s.nextInt();

quick_sort(a,0,n-1);

for(int i=0;i<n;i++)
System.out.print(a[i]+" ");
 }


  static void quick_sort(int a[],int st,int en)
  {
 if(st<en)
 {
       int k=pivot_ele(a,st,en);
  quick_sort(a,st,k);
  quick_sort(a,k+1,en);
 }
  }


  static int pivot_ele(int a[],int st,int en)
  {
 int i,j,pivot;
pivot=st;
i=st+1;
j=en;

while(i<=j)
{
while(a[i]<a[pivot] && i<en) i++;

while(a[j]>a[pivot]) j--;

if(i<=j)
{
int t=a[i];
a[i]=a[j];
a[j]=t;
i++;
j--;
}
}  ///while close

 int t=a[j];
a[j]=a[st];
a[st]=t;

return j;
    }
}

MERGE_SORT in java

import java.util.*;



class msort
{


 public static void main(String args[])
 {
Scanner s=new Scanner(System.in);
int n=s.nextInt();

        int a[]=new int [n];

for(int i=0;i<n;i++)
a[i]=s.nextInt();

merge_sort(a,0,n-1);

for(int i=0;i<n;i++)
System.out.print(a[i]+" ");

 }

  static void merge_sort(int a[],int st,int en)
  {
 if(st<en)
 {
       int k=(st+en)/2;
  merge_sort(a,st,k);
  merge_sort(a,k+1,en);
  merge(a,st,k,en);
 }
  }
 
    static void merge(int array[],int lowerIndex,int middle,int higherIndex)
{
int tempMergArr[]=new int[higherIndex-lowerIndex+1];

int k=0;
       for (int i = lowerIndex; i <= higherIndex; i++)
            tempMergArr[k++] = array[i];

        int i = lowerIndex;
int r=i;
        int j = middle + 1;
         k = lowerIndex;

        while (i <= middle && j <= higherIndex)
{
            if (tempMergArr[i-r] <= tempMergArr[j-r]) {
                array[k] = tempMergArr[i-r];
                i++;
            } else {
                array[k] = tempMergArr[j-r];
                j++;
            }
            k++;
        }


        while (i <=middle) {
            array[k] = tempMergArr[i-r];
            k++;
            i++;
        }

 while (j <=higherIndex) {
            array[k] = tempMergArr[j-r];
            k++;
            j++;
        }

    }
}

Similarity between Merge_sort and Quick_sort

Similarity between Merge_sort  and  Quick_sort

In quick sort , the main thing is to choose the PIVOT  element.

In Merge sort , the main thing is merging part.

java program for finding gcd ,lcm ,xor and addition (without using operators )

import java.util.*;

class LCM
{
 public static void main(String args[])
 {
   Scanner s=new Scanner(System.in);
   int k1 = s.nextInt();
   int k2= s.nextInt();
 
   int gcd=hcf(k1,k2);
   System.out.println(" hcf of these two number is "+gcd);
 
   int lcm=(k1*k2)/gcd;
   System.out.println(" lcm of these two number is "+lcm);
 
   int xor=k1^k2;
   System.out.println(" xor of these two number is " +xor);
 
   int addd=Add(k1,k2);
   System.out.println("addition method without using arthemetic operators is "+addd);
 
 
 }

 static int hcf(int a,int b)
 {
int r=a%(b);
int diviser=a;
int divident=b;
int quotient;
while(r>0)
{
  quotient=divident/diviser;
r=divident%diviser;
divident=diviser;
diviser=r;
}
return divident;
 }

 /*
 Sum of two bits can be obtained by performing XOR (^) of the two bits. Carry bit can be obtained by performing AND (&) of two bits.
Above is simple Half Adder logic that can be used to add 2 single bits. We can extend this logic for integers. If x and y don’t have set bits at same position(s), then bitwise XOR (^) of x and y gives the sum of x and y. To incorporate common set bits also, bitwise AND (&) is used. Bitwise AND of x and y gives all carry bits. We calculate (x & y) << 1 and add it to x ^ y to get the required result.
*/

  static int Add(int x, int y)
  {
    // Iterate till there is no carry
    while (y != 0)
    {
        // carry now contains common set bits of x and y
        int carry = x & y;

        // Sum of bits of x and y where at least one of the bits is not set
        x = x ^ y;

        // Carry is shifted by one so that adding it to x gives the required sum
        y = carry << 1;
    }
    return x;
  }


}

3 ways to take inputs in java (Scanner , console , BufferedReader )

import java.util.*;

import java.io.Console;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;



class Input
{
 public static void main(String []args) throws IOException
 {
  Scanner a = new Scanner(System.in); // creating object of scanner class
  String s=a.nextLine();              // way to take input through Scanner(nextLine for String)
  System.out.println(s);
  int i=a.nextInt();                  // way to take input through Scanner(nextInt for int)
  System.out.println(i);


  String str=System.console().readLine();  // way to take input from console
  System.out.println(str);



  BufferedReader in = new BufferedReader( new InputStreamReader(System.in)); // creating object of BufferedReader
  String str1 = in.readLine();      
  System.out.println(str1);
  int num = Integer.parseInt(in.readLine());
  System.out.println(num);

 }
}

A sample Python Program for Reference work ( Life Universe Everything )

1. def main():
3. while True:
5. w=input()
7. if w==42:
10. break
12. else :
14. print w
16. main()

-----------------------------------------------------------------------------------------=============================================================================================

I. Yet another A + B codeforces

def main():

            a=int(input())

            b=int(input())

            c=int(input())

           

            if a+b == c:

                print("YES")

            elif a+a == c:

                print("YES")

            elif b+b == c:

                print("YES")

            elif 2*c == b:

                print("YES")

            elif 2*a == b:

                print("YES")

            elif a+c == b:

                print("YES")

            elif 2*c == a:

                print("YES")

            elif 2*b == a:

                print("YES")

            elif c+b == a:

                print("YES")

            else:

                print("NO")

main()

A Sample PHP program for reference work( taking input ,creating arrays )

<?php fscanf(STDIN, "%d\n", $test); while($test--) { $ooo=array(); for($i=0;$i<26;$i++) $ooo[$i]=0; fscanf(STDIN, "%s\n", $raa); $qwe=0; $p=strlen($raa); for($i=0;$i<$p;$i++) { $w=ord($raa[$i]); $qwe= $w-97; $ooo[$qwe]=$ooo[$qwe]+1; } $f=0; $c=0; for($i=0;$i<26;$i++) { if($ooo[$i]%2!=0) { $f=1; $c++; } } if($f==0) { echo"Yes"; } else if($f==1 && strlen($raa)%2==1 && $c==1) { echo "Yes"; } else { echo "No"; } echo "<br>"; }