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ICSE Class 12 Computer Science Question 2 of 3

Solved 2020 Practical Paper ISC Computer Science — Question 2

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Question

Question 2

Write a program to declare a matrix A[][] of order (M x N) where 'M' is the number of rows and 'N' is the number of columns such that the value of 'M' must be greater than 0 and less than 10 and the value of 'N' must be greater than 2 and less than 6. Allow the user to input digits (0 - 7) only at each location, such that each row represents an octal number.

Example:

231(decimal equivalent of 1st row = 153 i.e. 2x82 + 3x81 + 1x80)
405(decimal equivalent of 2nd row = 261 i.e. 4x82 + 0x81 + 5x80)
156(decimal equivalent of 3rd row = 110 i.e. 1x82 + 5x81 + 6x80)

Perform the following tasks on the matrix:

  1. Display the original matrix.
  2. Calculate the decimal equivalent for each row and display as per the format given below.

Test your program for the following data and some random data:

Example 1:

INPUT:
M = 1
N = 3
ENTER ELEMENTS FOR ROW 1: 1 4 4

OUTPUT:

FILLED MATRIXDECIMAL EQUIVALENT
144100

Example 2:

INPUT:
M = 3
N = 4
ENTER ELEMENTS FOR ROW 1: 1 1 3 7
ENTER ELEMENTS FOR ROW 2: 2 1 0 6
ENTER ELEMENTS FOR ROW 3: 0 2 4 5

OUTPUT:

FILLED MATRIXDECIMAL EQUIVALENT
1137607
21061094
0245165

Example 3:

INPUT:
M = 3
N = 3
ENTER ELEMENTS FOR ROW 1: 2 4 8

OUTPUT:
INVALID INPUT

Example 4:

INPUT:
M = 4
N = 6

OUTPUT:
OUT OF RANGE

Solution
import java.util.Scanner;

public class OctalMatrix
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter the number of rows (M): ");
        int m = in.nextInt();
        System.out.print("Enter the number of columns (N): ");
        int n = in.nextInt();
        
        if (m <= 0 || m >= 10 || n <= 2 || n >= 6) {
            System.out.println("OUT OF RANGE");
            return;
        }
        
        int a[][] = new int[m][n];
        
        for (int i = 0; i < m; i++) {
            System.out.println("ENTER ELEMENTS FOR ROW " + (i + 1) + ": ");
            for (int j = 0; j < n; j++) {
                a[i][j] = in.nextInt();
                if (a[i][j] < 0 || a[i][j] > 7) {
                    System.out.println("INVALID INPUT");
                    return;
                }
            }
        }
        
        System.out.println("FILLED MATRIX\tDECIMAL EQUIVALENT");
        
        for (int i = 0; i < m; i++) {
            int decNum = 0;
            for (int j = 0; j < n; j++) {
                decNum += a[i][j] * Math.pow(8, n - j - 1 );
                System.out.print(a[i][j] + " ");
            }
            System.out.print("\t\t" + decNum);
            System.out.println();
        }
    }
}
Output
BlueJ output of OctalMatrix.java
BlueJ output of OctalMatrix.java
BlueJ output of OctalMatrix.java
BlueJ output of OctalMatrix.java
Answer

import
java.util.Scanner
;
public
class
OctalMatrix
{
public
static
void
main
(
String
args
[]) {
Scanner
in
=
new
Scanner
(
System
.
in);
System
.
out
.
print(
"
Enter the number of rows (M):
"
);
int
m
=
in
.
nextInt();
System
.
out
.
print(
"
Enter the number of columns (N):
"
);
int
n
=
in
.
nextInt();
if
(m
<=
0
||
m
>=
10
||
n
<=
2
||
n
>=
6
) {
System
.
out
.
println(
"
OUT OF RANGE
"
);
return
;
}
int
a[][]
=
new
int
[m][n];
for
(
int
i
=
0
; i
<
m; i
++
) {
System
.
out
.
println(
"
ENTER ELEMENTS FOR ROW
"
+
(i
+
1
)
+
"
:
"
);
for
(
int
j
=
0
; j
<
n; j
++
) {
a[i][j]
=
in
.
nextInt();
if
(a[i][j]
<
0
||
a[i][j]
>
7
) {
System
.
out
.
println(
"
INVALID INPUT
"
);
return
;
}
}
}
System
.
out
.
println(
"
FILLED MATRIX
\t
DECIMAL EQUIVALENT
"
);
for
(
int
i
=
0
; i
<
m; i
++
) {
int
decNum
=
0
;
for
(
int
j
=
0
; j
<
n; j
++
) {
decNum
+=
a[i][j]
*
Math
.
pow(
8
, n
-
j
-
1
);
System
.
out
.
print(a[i][j]
+
"
"
);
}
System
.
out
.
print(
"
\t\t
"
+
decNum);
System
.
out
.
println();
}
}
}
Output