Q: Question 2Differentiate between the following.i. Array Declaration and Initialisation

Array declaration tells the compiler about the size and data type of the array so that the compiler can reserve the required memory for the array. This reserved memory is still empty. Array Initialisation assigns values to the array elements i.e. it stores values in the memory reserved for the array elements.ii. int a[10] and char a[10]int a[10] is an array of int data type that can hold 10 integer values whereas char a[10] is an array of char data type that can hold 10 characters.iii. Sorting and SearchingSortingSearchingSorting means to arrange the elements of the array in ascending or descending order.Searching means to search for a term or value in an array.Bubble sort and Selection sort are examples of sorting techniques.Linear search and Binary search are examples of search techniques.iv. Linear search and Binary searchLinear SearchBinary SearchLinear search works on sorted and unsorted arraysBinary search works on only sorted arrays (ascending or descending)Each element of the array is checked against the target value until the element is found or end of the array is reachedArray is successively divided into 2 halves and the target element is searched either in the first half or in the second halfLinear Search is slowerBinary Search is fasterv. Selection sort and Bubble sortSelection sortBubble sortSelection Sort selects the smallest element from unsorted sub-array and swaps it with the leftmost unsorted element.Bubble Sort compares adjacent elements and swaps them if they are in wrong order.Performs lesser number of swaps to sort the same array relative to Bubble SortPerforms more number of swaps to sort the arraySelection Sort is fasterBubble Sort is slower

Q: Question 3How does the linear search find an element in the array? Explain your answer with a suitable example.

In linear search, we start at the first element of the array and sequentially check each element of the list for the search value until a match is found or all the elements have been searched. As soon as the search value is found, the algorithm quits and returns the position (index) of the target value in the array.For example, consider the following array:int arr[] = {1, 8, 4, 7, 5};We want to check if 7 is present in the array or not. Linear search will first check if 1 is equal to 7, then it will move on to the next element which is 8. It will keep doing this in a linear progression and when it reaches the element at index 3, it finds a match so it will give us this index 3 which means that 7 is present at index 3 of array arr.

Q: Question 4Explain the technique of Bubble Sort with an example.

Bubble Sort is a sorting algorithm that works by repeatedly iterating through the array, comparing each pair of adjoining elements and swapping them if they are in wrong order.For example, consider the following unsorted array:9523Pass 1First 9 is compared with 5 and as 9 is greater than 5 the elements are swapped:5923Next, 9 is compared with 2 and as 9 is greater than 2 the elements are swapped:5293Next, 9 is compared with 3 and as 9 is greater than 3 the elements are swapped:5239At the end of first pass, the highest element of the array is at the last position.Pass 25 is compared with 2 and as 5 is greater than 2 the elements are swapped:2539Next, 5 is compared with 3 and as 5 is greater than 3 the elements are swapped:2359At the end of first pass, the second highest element of the array is in its correct position.Pass 32 is compared with 3 and as 2 is less then 3 no swapping takes place.2359With this, the third and final pass ends and the elements of the array are in sorted order.

Q: Question 5Explain the technique of Selection Sort with an example.

Selection Sort divides the array into two parts — sorted sub-array and unsorted sub-array. In each pass, it finds the minimum element of the unsorted sub-array and swaps it with the leftmost unsorted element moving the sorted sub-array one element to the right.For example, consider the following unsorted array:9523Pass 1At the start, the smallest element of the array is selected (which is 2) and swapped with the element at 0th index (which is 9):2593At the end of the first pass, the smallest element is in its correct position. Length of sorted sub-array is 1 and unsorted sub-array is 3.Pass 2The smallest element of the unsorted sub-array is selected (which is 3) and swapped with the element at 1st index (which is 5):2395At the end of the second pass, length of sorted sub-array is 2 and unsorted sub-array is 2.Pass 3The smallest element of the unsorted sub-array is selected (which is 5) and swapped with the element at 2nd index (which is 9):2359With this, the third and final pass ends and the elements of the array are in sorted order.

Q: Question 6Why does Binary Search need a sorted array to perform the search operation?

In Binary Search, the array is repeatedly divided into two halves and the element is searched in that half whose last element is greater than or equal to the element being searched. For this reason, Binary Search needs a sorted array to perform the search operation.

Q: Question 7How is one-dimensional array represented in memory ?

Single-dimensional arrays are lists of information of the same type and their elements are stored in contiguous memory locations in their index order.For example, an array grade of type char with 8 elements declared aschar grade[ ] = new char[8];will have the element grade[0] at the first allocated memory location, grade[1] at the next contiguous memory location, grade[2] at the next, and so forth. Since grade is a char type array, each element size is 2 bytes and it will be represented in memory as shown in the figure given below:

Q: Question 8Write a program to input integer elements into an array of size 20 and perform the following operations:Display largest number from the arrayDisplay smallest number from the arrayDisplay sum of all the elements of the array

import java.util.Scanner; public class KboatSDAMinMaxSum { public static void main(String args[]) { Scanner in = new Scanner(System.in); int arr[] = new int[20]; System.out.println("Enter 20 numbers:"); for (int i = 0; i < 20; i++) { arr[i] = in.nextInt(); } int min = arr[0], max = arr[0], sum = 0; for (int i = 0; i < arr.length; i++) { if (arr[i] < min) min = arr[i]; if (arr[i] > max) max = arr[i]; sum += arr[i]; } System.out.println("Largest Number = " + max); System.out.println("Smallest Number = " + min); System.out.println("Sum = " + sum); } }Output

Q: Question 12Write a code segment to compute the sum of all positive real numbers stored in the following array.double numb[] = new double[50];

double sum = 0; for (int i = 0; i < 50; i++) { if (numb[i] > 0) { sum += numb[i]; } } System.out.println("Sum of positive real numbers = " + sum);

Question 1

Question 1Write a program to initialise the given data in an array and find the minimum and maximum values along with the sum of the given elements.Numbers: 2, 5, 4, 1, 3Output:Minimum value: 1Maximum value: 5Sum of the elements: 15

Accepted Answer

public class KboatMinMaxSum
{
    public static void main(String args[]) {
        int arr[] = {2, 5, 4, 1, 3};
        
        int max = arr[0];
        int min = arr[0];
        int sum = 0;
        
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] > max)
                max = arr[i];
                
            if (arr[i] < min)
                min = arr[i];
                
            sum += arr[i];
        }
        
        System.out.println("Minimum value: " + min);
        System.out.println("Maximum value: " + max);
        System.out.println("Sum of the elements: " + sum);
    }
}Output

Question 2

Question 2Differentiate between the following.i. Array Declaration and Initialisation

Accepted Answer

Array declaration tells the compiler about the size and data type of the array so that the compiler can reserve the required memory for the array. This reserved memory is still empty. Array Initialisation assigns values to the array elements i.e. it stores values in the memory reserved for the array elements.ii. int a[10] and char a[10]int a[10] is an array of int data type that can hold 10 integer values whereas char a[10] is an array of char data type that can hold 10 characters.iii. Sorting and SearchingSortingSearchingSorting means to arrange the elements of the array in ascending or descending order.Searching means to search for a term or value in an array.Bubble sort and Selection sort are examples of sorting techniques.Linear search and Binary search are examples of search techniques.iv. Linear search and Binary searchLinear SearchBinary SearchLinear search works on sorted and unsorted arraysBinary search works on only sorted arrays (ascending or descending)Each element of the array is checked against the target value until the element is found or end of the array is reachedArray is successively divided into 2 halves and the target element is searched either in the first half or in the second halfLinear Search is slowerBinary Search is fasterv. Selection sort and Bubble sortSelection sortBubble sortSelection Sort selects the smallest element from unsorted sub-array and swaps it with the leftmost unsorted element.Bubble Sort compares adjacent elements and swaps them if they are in wrong order.Performs lesser number of swaps to sort the same array relative to Bubble SortPerforms more number of swaps to sort the arraySelection Sort is fasterBubble Sort is slower

Question 3

Question 3How does the linear search find an element in the array? Explain your answer with a suitable example.

Accepted Answer

In linear search, we start at the first element of the array and sequentially check each element of the list for the search value until a match is found or all the elements have been searched. As soon as the search value is found, the algorithm quits and returns the position (index) of the target value in the array.For example, consider the following array:int arr[] = {1, 8, 4, 7, 5};We want to check if 7 is present in the array or not. Linear search will first check if 1 is equal to 7, then it will move on to the next element which is 8. It will keep doing this in a linear progression and when it reaches the element at index 3, it finds a match so it will give us this index 3 which means that 7 is present at index 3 of array arr.

Question 4

Question 4Explain the technique of Bubble Sort with an example.

Accepted Answer

Bubble Sort is a sorting algorithm that works by repeatedly iterating through the array, comparing each pair of adjoining elements and swapping them if they are in wrong order.For example, consider the following unsorted array:9523Pass 1First 9 is compared with 5 and as 9 is greater than 5 the elements are swapped:5923Next, 9 is compared with 2 and as 9 is greater than 2 the elements are swapped:5293Next, 9 is compared with 3 and as 9 is greater than 3 the elements are swapped:5239At the end of first pass, the highest element of the array is at the last position.Pass 25 is compared with 2 and as 5 is greater than 2 the elements are swapped:2539Next, 5 is compared with 3 and as 5 is greater than 3 the elements are swapped:2359At the end of first pass, the second highest element of the array is in its correct position.Pass 32 is compared with 3 and as 2 is less then 3 no swapping takes place.2359With this, the third and final pass ends and the elements of the array are in sorted order.

Question 5

Question 5Explain the technique of Selection Sort with an example.

Accepted Answer

Selection Sort divides the array into two parts — sorted sub-array and unsorted sub-array. In each pass, it finds the minimum element of the unsorted sub-array and swaps it with the leftmost unsorted element moving the sorted sub-array one element to the right.For example, consider the following unsorted array:9523Pass 1At the start, the smallest element of the array is selected (which is 2) and swapped with the element at 0th index (which is 9):2593At the end of the first pass, the smallest element is in its correct position. Length of sorted sub-array is 1 and unsorted sub-array is 3.Pass 2The smallest element of the unsorted sub-array is selected (which is 3) and swapped with the element at 1st index (which is 5):2395At the end of the second pass, length of sorted sub-array is 2 and unsorted sub-array is 2.Pass 3The smallest element of the unsorted sub-array is selected (which is 5) and swapped with the element at 2nd index (which is 9):2359With this, the third and final pass ends and the elements of the array are in sorted order.

Question 6

Question 6Why does Binary Search need a sorted array to perform the search operation?

Accepted Answer

In Binary Search, the array is repeatedly divided into two halves and the element is searched in that half whose last element is greater than or equal to the element being searched. For this reason, Binary Search needs a sorted array to perform the search operation.

Question 7

Question 7How is one-dimensional array represented in memory ?

Accepted Answer

Single-dimensional arrays are lists of information of the same type and their elements are stored in contiguous memory locations in their index order.For example, an array grade of type char with 8 elements declared aschar grade[ ] = new char[8];will have the element grade[0] at the first allocated memory location, grade[1] at the next contiguous memory location, grade[2] at the next, and so forth. Since grade is a char type array, each element size is 2 bytes and it will be represented in memory as shown in the figure given below:

Question 8

Question 8Write a program to input integer elements into an array of size 20 and perform the following operations:Display largest number from the arrayDisplay smallest number from the arrayDisplay sum of all the elements of the array

Accepted Answer

import java.util.Scanner;

public class KboatSDAMinMaxSum
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int arr[] = new int[20];
        System.out.println("Enter 20 numbers:");
        for (int i = 0; i < 20; i++) {
            arr[i] = in.nextInt();
        }
        int min = arr[0], max = arr[0], sum = 0;
        for (int i = 0; i < arr.length; i++) {
            if (arr[i] < min)
                min = arr[i];
                
            if (arr[i] > max)
                max = arr[i];
                
            sum += arr[i];
        }
        
        System.out.println("Largest Number = " + max);
        System.out.println("Smallest Number = " + min);
        System.out.println("Sum = " + sum);
    }
}Output

Question 9

Question 10Suppose x is an array of type int[] with 50 elements. Write a code segment that will count and print the frequency of number 42 in the array.

Accepted Answer

int c = 0;
for (int i = 0; i < 50; i++) {
    if (x[i] == 42) {
        c++;
    }
}
System.out.println("Frequency of 42 = " + c);

Question 10

Question 12Write a code segment to compute the sum of all positive real numbers stored in the following array.double numb[] = new double[50];

Accepted Answer

double sum = 0;
for (int i = 0; i < 50; i++) {
    if (numb[i] > 0) {
        sum += numb[i];
    }
}
System.out.println("Sum of positive real numbers = " + sum);

Question 11

Question 13Write a code segment that finds the largest integer in this two-dimensional array.int data[][] = new int[5][5];

Accepted Answer

int l = data[0][0];
for (int i = 0; i < 5; i++) {
    for (int j = 0; j < 5; j++) {
        if (data[i][j] > l) {
            l = data[i][j];
        }
    }
}
System.out.println("Largest Element = " + l);

Question 12

Question 14Given the following declarations:final int SIZE = 20;
char[] name = new char[SIZE];i. Write an assignment statement that stores 'D' into the first element of the array name.ii. Write an output statement that prints the value of the tenth element of the array name.iii. Write a for statement that fills the array name with spaces.

Accepted Answer

i. name[0] = 'D';ii. System.out.println(name[9]);iii. For Statement:for (int i = 0; i < SIZE; i++) {
    name[i] = ' ';
}

Question 13

Question 14(ii)Declare following arrays: check of 100 short element.

Accepted Answer

short check[] = new short[100];

Question 14

Question 16Write Java statements for the following:i. Create an array to hold 15 double values.ii. Assign the value 10.5 to the last element in the array.iii. Display the sum of the first and the last element.iv. Write a loop that computes the sum of all elements in the array.

Accepted Answer

i. Create an array to hold 15 double values.double arr[] = new double[15];ii. Assign the value 10.5 to the last element in the array.arr[14] = 10.5;iii. Display the sum of the first and the last element.double r = arr[0] + arr[14];
System.out.println("Result = " + r);iv. Write a loop that computes the sum of all elements in the array.double sum = 0;
for (int i = 0; i < 15; i++) {
    sum += arr[i];
}
System.out.println("Sum = " + sum);

Question 15

Question 17Write a program to accept the year of graduation from school as an integer value from the user. Using the binary search technique on the sorted array of integers given below, output the message "Record exists" if the value input is located in the array. If not, output the message "Record does not exist".Sample Input:n[0]n[1]n[2]n[3]n[4]n[5]n[6]n[7]n[8]n[9]1982198719931996199920032006200720092010

Accepted Answer

import java.util.Scanner;

public class KboatGraduationYear
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int n[] = {1982, 1987, 1993, 1996, 1999, 2003, 2006, 2007, 2009, 2010};
        
        System.out.print("Enter graduation year to search: ");
        int year = in.nextInt();
        
        int l = 0, h = n.length - 1, idx = -1;
        while (l <= h) {
            int m = (l + h) / 2;
            if (n[m] == year) {
                idx = m;
                break;
            }
            else if (n[m] < year) {
                l = m + 1;
            }
            else {
                h = m - 1;
            }
        }
        
        if (idx == -1)
            System.out.println("Record does not exist");
        else
            System.out.println("Record exists");
    }
}Output

Question 16

Question 18Write a program that reads ten integers and displays them in the reverse order in which they were read.

Accepted Answer

import java.util.Scanner;

public class KboatSDAReverse
{
    public static void main(String args[]) {
        
        Scanner in = new Scanner(System.in);
        int arr[] = new int[10];
        
        System.out.println("Enter 10 integers:");
        for (int i = 0; i < 10; i++) {
            arr[i] = in.nextInt();
        }
        
        System.out.println("Integers in reverse order:");
        for (int i = 9; i >= 0; i--) {
            System.out.print(arr[i] + " ");
        }
    }
}Output

Question 17

Question 19Write a program that reads a long number, counts and displays the occurrences of each digit in it.

Accepted Answer

import java.util.Scanner;

public class KboatSDANumber
{
    public static void main(String args[]) {
        
        Scanner in = new Scanner(System.in);
        System.out.print("Enter a number: ");
        long num = in.nextLong();
        int dCount[] = new int[10];

while (num != 0) {
            int d = (int)(num % 10);
            dCount[d] = dCount[d] + 1;
            num /= 10;
        }
        
        System.out.println("Digit	Occurence");
        for (int i = 0; i < 10; i++) {
            if (dCount[i] != 0) {
                System.out.println(i + "	" + dCount[i]);
            }
        }
    }
}Output

Question 18

Question 20Write a program to input 10 integer elements in an array and sort them in descending order using bubble sort technique.

Accepted Answer

import java.util.Scanner;

public class KboatBubbleSortDsc
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        int n = 10;
        int arr[] = new int[n];
        
        System.out.println("Enter the elements of the array:");
        for (int i = 0; i < n; i++) {
            arr[i] = in.nextInt();
        }
        
        //Bubble Sort
        for (int i = 0; i < n - 1; i++) {
            for (int j = 0; j < n - i - 1; j++) {
                if (arr[j] < arr[j + 1]) {
                    int t = arr[j];
                    arr[j] = arr[j+1];
                    arr[j+1] = t;
                }
            } 
        }
        
        System.out.println("Sorted Array:");
        for (int i = 0; i < n; i++) {
            System.out.print(arr[i] + " ");
        }
    }
}Output

Question 19

Question 21Write a program to perform binary search on a list of integers given below, to search for an element input by the user. If it is found display the element along with its position, otherwise display the message "Search element not found".5, 7, 9, 11, 15, 20, 30, 45, 89, 97

Accepted Answer

import java.util.Scanner;

public class KboatBinarySearch
{
    public static void main(String args[]) {
        
        Scanner in = new Scanner(System.in);
        int arr[] = {5, 7, 9, 11, 15, 20, 30, 45, 89, 97};
        
        System.out.print("Enter number to search: ");
        int n = in.nextInt();
        
        int l = 0, h = arr.length - 1, index = -1;
        while (l <= h) {
            int m = (l + h) / 2;
            if (arr[m] < n)
                l = m + 1;
            else if (arr[m] > n)
                h = m - 1;
            else {
                index = m;
                break;
            }
                
        }
        
        if (index == -1) {
            System.out.println("Search element not found");
        }
        else {
            System.out.println(n + " found at position " + index);
        }
    }
}Output

Question 20

Question 22Write a program to store 6 elements in an array P and 4 elements in an array Q. Now, produce a third array R, containing all the elements of array P and Q. Display the resultant array.InputInputOutputP[ ]Q[ ]R[ ]419462361712823 310 10  19  23  7  8

Accepted Answer

import java.util.Scanner;

public class Kboat3Arrays
{
    public static void main(String args[]) {
        
        Scanner in = new Scanner(System.in);
        
        int P[] = new int[6];
        int Q[] = new int[4];
        int R[] = new int[10];
        int i = 0;
        
        System.out.println("Enter 6 elements of array P:");
        for (i = 0; i < P.length; i++) {
            P[i] = in.nextInt();
        }
        
        System.out.println("Enter 4 elements of array Q:");
        for (i = 0; i < Q.length; i++) {
            Q[i] = in.nextInt();
        }
        
        i = 0;
        while(i < P.length) {
            R[i] = P[i];
            i++;
        }
        
        int j = 0;
        while(j < Q.length) {
            R[i++] = Q[j++];
        }
        
        System.out.println("Elements of Array R:");
        for (i = 0; i < R.length; i++) {
            System.out.print(R[i] + " ");
        }
    }
}Output

Arrays

Assignment Questions

Objective Type Questions