Programs asked in interviews

Find out square root of a given number without using any built-in functions

    public static void findSquareRoot(double number)

    {

        boolean isPositiveNumber = true;

        double g1;

        //if the number given is a 0

        if(number==0)

        {

            System.out.println("Square root of "+number+" = "+0);

        }

        //If the number given is a -ve number

        else if(number<0)

        {

            number=-number;

            isPositiveNumber = false;

        }

        //Proceeding to find out square root of the number

        double squareRoot = number/2;

        do

        {

            g1=squareRoot;

            squareRoot = (g1 + (number/g1))/2;

        }

        while((g1-squareRoot)!=0);

        //Displays square root in the case of a positive number

        if(isPositiveNumber)

        {

            System.out.println("Square roots of "+number+" are ");

            System.out.println("+"+squareRoot);

            System.out.println("-"+squareRoot);

        }

        //Displays square root in the case of a -ve number

        else

        {

            System.out.println("Square roots of -"+number+" are ");

            System.out.println("+"+squareRoot+" i");

            System.out.println("-"+squareRoot+" i");

        }

    }

Find out if a year is LEAP Year

//Flag to store the test result

        boolean isLeapYear = false;

        if(year % 400 == 0)

        {

            isLeapYear = true; //400 -> TRUE

        }

        else if (year % 100 == 0)

        {

            isLeapYear = false; //100 -> FALSE

        }

        else if(year % 4 == 0)

        {

            isLeapYear = true; //4 -> TRUE

        }

        else

        {

            isLeapYear = false;

        }

Find out 2^n

            int power = 1;

            int i = 0;

            System.out.println("Powers of 2 that are less than 2^"+n);

            while (i <= n)

            {

                System.out.println("2^"+i+" = " + power);

                power = power * 2;

                i++;

            }

        }

 Generate Fibonacci series

        //Assigning the first two elements

        long[] FibonacciSeries = new long[limit];

        FibonacciSeries[0] = 0;

        FibonacciSeries[1] = 1;

        //Generates the Fibonacci series and store it in the array FibonacciSeries

        for(int i=2; i < limit; i++)

        {

            FibonacciSeries[i] = FibonacciSeries[i-1] + FibonacciSeries[i-2];

        }