Saturday, July 20, 2024

Java Technical Interview Questions and Answers 2

1)


first non repeating character

Malayalam

y

programming

p



class HelloWorld {

    public static void main(String[] args) {

        String str = "MalayalaM";

       

        char a = '\0'; 

        for (char c : str.toCharArray()) {

            if (str.indexOf(c) == str.lastIndexOf(c)) {

                a = c;

                break;

            }

           

        }


        System.out.println(a);

        

    }

}


2)



1

##

333

####

55555



class HelloWorld {

    public static void main(String[] args) {

        for(int i=1;i<=5;i++)

        {

            for(int j=1;j<=i;j++)

            {

                if(i%2!=0)

                {

                    System.out.print(i);

                }

                else

                {

                    System.out.print("#");

                }

            }

            System.out.println();

        }

        

    }

}


3)


find two elements of array for given target sum





class HelloWorld {

    public static void main(String[] args) {

        int[] a = {2, 11, 7, 15};

        int target = 9;

        

       

        for (int i = 0; i < a.length; i++) {

            for (int j = i + 1; j < a.length; j++) {

                if (a[i] + a[j] == target) {

                System.out.println(a[i] + ", " + a[j]);

                }

            }

        }

        

    }

}




4)

find union of two arrays



int a[]={1,2,3,4,5};

int b[]={3,2,6,7,8};



output


[1, 2, 3, 4, 5, 6, 7, 8]



import java.util.*;

class HelloWorld {

    public static void main(String[] args) {

        int a[]={1,2,3,4,5};

int b[]={3,2,6,7,8};

HashSet<Integer> s=new HashSet<Integer>();

for(int i=0;i<5;i++)

{

    s.add(a[i]);

}

for(int i=0;i<5;i++)

{

    s.add(b[i]);

}

        System.out.println(s);

        

    }

}



5)


find intersection of two arrays



int a[]={1,2,3,4,5};

int b[]={3,2,6,7,8};



output


{2,3}



import java.util.*;

class HelloWorld {

    public static void main(String[] args) {

        int a[]={1,2,3,4,5};

int b[]={3,2,6,7,8};


for(int i=0;i<5;i++)

{

    for(int j=0;j<=i;j++)

    {

        if(a[i]==b[j])

        {

            System.out.println(a[i]);

        }

    }

}



    }

}



6)Check if a String is a Palindrome


import java.util.*;

class HelloWorld {

    public static void main(String[] args) {

       String a="mam";

       StringBuilder b = new StringBuilder(a);

        b.reverse();


    if(a.equals(b.toString()))

    {

        System.out.println("polindrome");

    }

    else

    {

        System.out.println("not polindrome");

    }

    }

}



7)remove duplicate in array


import java.util.*;

class HelloWorld {

    public static void main(String[] args) {

    String a="sabari";

    char c[]=a.toCharArray();

    LinkedHashSet<Character> d=new LinkedHashSet<Character>();

    for(char c1:c)

    {

        d.add(c1);

    }

    StringBuilder sb = new StringBuilder();

for (Character c2 : d) {

    sb.append(c2);

}

System.out.println(sb);

   

    

    }

}




8)

Given an array A[] and a number x, check for pair in A[] with sum as x.


Input

 {2, 11, 7,3,6, 15}


output


2, 7

3, 6

total count 2




9)

 first occurrence of a string in another string


 a = "Hello, how are you?";

 b = "how";


First occurrence of how is at index: 7



import java.util.*;

class HelloWorld {

    public static void main(String[] args) {

  String a = "Hello, how are you?";

String b = "how";


int index = a.indexOf(b);


if (index != -1) {

    System.out.println("First occurrence of "+ b +" is at index: " + index);

} else {

    System.out.println(" not found.");

}


   

    

    }

}




10)Shuffle array


import java.util.*;

class HelloWorld {

    public static void main(String[] args) {


int a[]={1,2,3,4,5,6};

 ArrayList<Integer> al=new ArrayList<Integer>();

 for(int i=0;i<a.length;i++)

 {

 al.add(a[i]);

 }

Collections.shuffle(al);


 System.out.println(al);

 

    

    }

}



11)Number of occurrence



X = 2

Arr[] = {1, 1, 2, 2, 2, 2, 3}

Output: 4

Explanation: 2 occurs 4 



import java.util.*;

class HelloWorld {

    public static void main(String[] args) {

int a[] = {1, 1, 2, 2, 2, 2, 3};

int x=2,count=0;


for(int i=0;i<a.length;i++)

{

    if(a[i]==x)

    {

        count++;

    }

}

 

 System.out.println(x+" occurs "+count);

    

    }

}



Input:



use abc;

CREATE TABLE Worker (

WORKER_ID INT NOT NULL PRIMARY KEY AUTO_INCREMENT,

FIRST_NAME CHAR(25),

LAST_NAME CHAR(25),

SALARY INT(15),

JOINING_DATE DATETIME,

DEPARTMENT CHAR(25)

);


INSERT INTO Worker 

(WORKER_ID, FIRST_NAME, LAST_NAME, SALARY, JOINING_DATE, DEPARTMENT) VALUES

(001, 'Monika', 'Arora', 100000, '21-02-20 09.00.00', 'HR'),

(002, 'Niharika', 'Verma', 80000, '21-06-11 09.00.00', 'Admin'),

(003, 'Vishal', 'Singhal', 300000, '21-02-20 09.00.00', 'HR'),

(004, 'Amitabh', 'Singh', 500000, '21-02-20 09.00.00', 'Admin'),

(005, 'Vivek', 'Bhati', 500000, '21-06-11 09.00.00', 'Admin'),

(006, 'Vipul', 'Diwan', 200000, '21-06-11 09.00.00', 'Account'),

(007, 'Satish', 'Kumar', 75000, '21-01-20 09.00.00', 'Account'),

(008, 'Geetika', 'Chauhan', 90000, '21-04-11 09.00.00', 'Admin');






Q. Write a SQL query to find the 3th highest salary from employee table?



SELECT DISTINCT salary

FROM worker

ORDER BY salary DESC

LIMIT 1 OFFSET 2;





Q. SQL queries

-- 2> Write a SQL query to find top n records?

-- Example: finding top 5 records from employee table



SELECT *

FROM worker

ORDER BY salary DESC

LIMIT 5;





-- 3> Write a SQL query to find the count of employees working in department 'Admin'


select count(*) from worker where department='Admin'


-- 4> Write a SQL query to fetch department wise count employees sorted by department count in desc order.



SELECT department, COUNT(*) AS empcount

FROM worker

GROUP BY department

ORDER BY empcount DESC;






-- 5> Write a SQL query to find only odd rows from employee table




SELECT *

FROM worker

WHERE worker_id % 2 <> 0;




6> Write a SQL query to show the last record from a table.


SELECT *

FROM worker

order by worker_id desc limit 1;





-- 7> Write a SQL query to show the first record from a table.


SELECT *

FROM worker

 limit 1;



-- 8> Write a SQL query to get last five records from a employee table.


SELECT *

FROM worker

order by worker_id desc limit 5;




-- 9> Write a SQL query to find employees having the highest salary in each department. 


select * from worker where salary in (select max(salary) from worker group by department )




-- 10> Write a SQL query to fetch departments along with the total salaries paid for each of them.


select department,sum(salary) from worker group by department





-- 11> write a SQL query to find employees with same salary



SELECT e1.*

FROM worker e1

JOIN worker e2 ON e1.salary = e2.salary

WHERE e1.worker_id!=e2.worker_id;














 

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Python Technical Interview Questions

 1)first non repeating character Malayalam y programming p str = "MalayalaM" a = '\0' for c in str:     if str.index(c) ==...