Discuss the following code:
Q: Magic squares. An n × n matrix that is filled with the numbers 1, 2, 3, ... , n2 is a magic square if the sum of the elements in each row, in each column, and in the two diagonals is the same value. For example,
Write a program that reads in n2 values from the keyboard and tests whether they form a magic square when arranged as a square matrix. You need to test three features:
• Did the user enter n2 numbers for some n?
• Do each of the numbers 1, 2, ... , n2 occur exactly once in the user input?
• When the numbers are put into a square, are the sums of the rows, columns, and diagonals equal to each other?
If the size of the input is a square, test whether all numbers between 1 and n2 are present. Then compute the row, column, and diagonal sums. Implement a class Square with methods
public void add(int i)
public boolean isMagic()
Here is a sample program run:
Enter a sequence of integers, followed by Q:
16 3 2 13 5 10 11 8 9 6 7 12 4 15 14 1
Q
It is a magic square.
Use the following class as your main class:
import java.util.ArrayList;
import java.util.Scanner;
/**
This class tests whether a sequence of inputs forms a magic square.
*/
public class MagicSquareChecker
{
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
Square sq = new Square();
System.out.println("Enter a sequence of integers, followed by Q: ");
while (in.hasNextInt())
{
sq.add(in.nextInt());
}
if(sq.isMagic())
System.out.println("It is a magic square.");
else
System.out.println("It is not a magic square.");
}
}