Solved 2016 Practical Paper ISC Computer Science — Question 2
Back to all questionsQuestion 2
Write a program to declare a square matrix A[][] of order (M × M) where 'M' must be greater than 3 and less than 10. Allow the user to input positive integers into this matrix. Perform the following tasks on the matrix:
- Sort the non-boundary elements in ascending order using any standard sorting technique and rearrange them in the matrix.
- Calculate the sum of both the diagonals.
- Display the original matrix, rearranged matrix and only the diagonal elements of the rearranged matrix with their sum.
Test your program for the following data and some random data:
Example 1
INPUT:
M = 4
9 2 1 5
8 13 8 4
15 6 3 11
7 12 23 8
OUTPUT:
ORIGINAL MATRIX
9 2 1 5
8 13 8 4
15 6 3 11
7 12 23 8
REARRANGED MATRIX
9 2 1 5
8 3 6 4
15 8 13 11
7 12 23 8
DIAGONAL ELEMENTS
9 5
3 6
8 13
7 8
SUM OF THE DIAGONAL ELEMENTS = 59
Example 2
INPUT:
M = 5
7 4 1 9 5
8 2 6 10 19
13 1 3 5 1
10 0 5 12 16
1 8 17 6 8
OUTPUT:
ORIGINAL MATRIX
7 4 1 9 5
8 2 6 10 19
13 1 3 5 1
10 0 5 12 16
1 8 17 6 8
REARRANGED MATRIX
7 4 1 9 5
8 0 1 2 19
13 3 5 5 1
10 6 10 12 16
1 8 17 6 8
DIAGONAL ELEMENTS
7 5
0 2
5
6 12
1 8
SUM OF THE DIAGONAL ELEMENTS = 46
Example 3
INPUT:
M = 3
OUTPUT:
THE MATRIX SIZE IS OUT OF RANGE.
Solution
import java.util.Scanner;
public class MatrixSort
{
public static void main(String args[]) {
Scanner in = new Scanner(System.in);
System.out.print("ENTER MATRIX SIZE (M): ");
int m = in.nextInt();
if (m <= 3 || m >= 10) {
System.out.println("THE MATRIX SIZE IS OUT OF RANGE.");
return;
}
int a[][] = new int[m][m];
System.out.println("ENTER ELEMENTS OF MATRIX");
for (int i = 0; i < m; i++) {
System.out.println("ENTER ROW " + (i+1) + ":");
for (int j = 0; j < m; j++) {
a[i][j] = in.nextInt();
/*
* Only positive integers
* should be enetered
*/
if (a[i][j] < 0) {
System.out.println("INVALID INPUT");
return;
}
}
}
System.out.println("ORIGINAL MATRIX");
printMatrix(a, m);
sortNonBoundaryMatrix(a, m);
System.out.println("REARRANGED MATRIX");
printMatrix(a, m);
computePrintDiagonalSum(a, m);
}
public static void sortNonBoundaryMatrix(int a[][], int m) {
/*
* To sort non-boundary elements of Matrix
* copy the non-boundary elements in a
* single dimensional array. Sort the
* single dimensional array and assign the
* sorted elements back in the 2D array at
* their respective positions
*/
int b[] = new int[(m - 2) * (m - 2)];
int k = 0;
for (int i = 1; i < m - 1; i++) {
for (int j = 1; j < m - 1; j++) {
b[k++] = a[i][j];
}
}
for (int i = 0; i < k - 1; i++) {
for (int j = 0; j < k - i - 1; j++) {
if (b[j] > b[j + 1]) {
int t = b[j];
b[j] = b[j+1];
b[j+1] = t;
}
}
}
k = 0;
for (int i = 1; i < m - 1; i++) {
for (int j = 1; j < m - 1; j++) {
a[i][j] = b[k++];
}
}
}
public static void computePrintDiagonalSum(int a[][], int m) {
int sum = 0;
System.out.println("DIAGONAL ELEMENTS");
for (int i = 0; i < m; i++) {
for (int j = 0; j < m; j++) {
if (i == j || i + j == m - 1) {
sum += a[i][j];
System.out.print(a[i][j] + "\t");
}
else {
System.out.print("\t");
}
}
System.out.println();
}
System.out.println("SUM OF THE DIAGONAL ELEMENTS = " + sum);
}
public static void printMatrix(int a[][], int m) {
for (int i = 0; i < m; i++) {
for (int j = 0; j < m; j++) {
System.out.print(a[i][j] + "\t");
}
System.out.println();
}
}
}Output
import
java.util.Scanner
;
public
class
MatrixSort
{
public
static
void
main
(
String
args
[]) {
Scanner
in
=
new
Scanner
(
System
.
in);
System
.
out
.
print(
"
ENTER MATRIX SIZE (M):
"
);
int
m
=
in
.
nextInt();
if
(m
<=
3
||
m
>=
10
) {
System
.
out
.
println(
"
THE MATRIX SIZE IS OUT OF RANGE.
"
);
return
;
}
int
a[][]
=
new
int
[m][m];
System
.
out
.
println(
"
ENTER ELEMENTS OF MATRIX
"
);
for
(
int
i
=
0
; i
<
m; i
++
) {
System
.
out
.
println(
"
ENTER ROW
"
+
(i
+
1
)
+
"
:
"
);
for
(
int
j
=
0
; j
<
m; j
++
) {
a[i][j]
=
in
.
nextInt();
/*
* Only positive integers
* should be enetered
*/
if
(a[i][j]
<
0
) {
System
.
out
.
println(
"
INVALID INPUT
"
);
return
;
}
}
}
System
.
out
.
println(
"
ORIGINAL MATRIX
"
);
printMatrix(a, m);
sortNonBoundaryMatrix(a, m);
System
.
out
.
println(
"
REARRANGED MATRIX
"
);
printMatrix(a, m);
computePrintDiagonalSum(a, m);
}
public
static
void
sortNonBoundaryMatrix
(
int
a
[][],
int
m
) {
/*
* To sort non-boundary elements of Matrix
* copy the non-boundary elements in a
* single dimensional array. Sort the
* single dimensional array and assign the
* sorted elements back in the 2D array at
* their respective positions
*/
int
b[]
=
new
int
[(m
-
2
)
*
(m
-
2
)];
int
k
=
0
;
for
(
int
i
=
1
; i
<
m
-
1
; i
++
) {
for
(
int
j
=
1
; j
<
m
-
1
; j
++
) {
b[k
++
]
=
a[i][j];
}
}
for
(
int
i
=
0
; i
<
k
-
1
; i
++
) {
for
(
int
j
=
0
; j
<
k
-
i
-
1
; j
++
) {
if
(b[j]
>
b[j
+
1
]) {
int
t
=
b[j];
b[j]
=
b[j
+
1
];
b[j
+
1
]
=
t;
}
}
}
k
=
0
;
for
(
int
i
=
1
; i
<
m
-
1
; i
++
) {
for
(
int
j
=
1
; j
<
m
-
1
; j
++
) {
a[i][j]
=
b[k
++
];
}
}
}
public
static
void
computePrintDiagonalSum
(
int
a
[][],
int
m
) {
int
sum
=
0
;
System
.
out
.
println(
"
DIAGONAL ELEMENTS
"
);
for
(
int
i
=
0
; i
<
m; i
++
) {
for
(
int
j
=
0
; j
<
m; j
++
) {
if
(i
==
j
||
i
+
j
==
m
-
1
) {
sum
+=
a[i][j];
System
.
out
.
print(a[i][j]
+
"
\t
"
);
}
else
{
System
.
out
.
print(
"
\t
"
);
}
}
System
.
out
.
println();
}
System
.
out
.
println(
"
SUM OF THE DIAGONAL ELEMENTS =
"
+
sum);
}
public
static
void
printMatrix
(
int
a
[][],
int
m
) {
for
(
int
i
=
0
; i
<
m; i
++
) {
for
(
int
j
=
0
; j
<
m; j
++
) {
System
.
out
.
print(a[i][j]
+
"
\t
"
);
}
System
.
out
.
println();
}
}
}
Output