Question

Can anyone show me how to use linked list data structure to store a 3x3 matrix in a file in Java? Please show me the code.

You should read the matrix in the file first and use the linked list data structure to store it then print it out to the screen.

Answer 1

Java code:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class Main
{
  
  
  
static class Node {
int data;
Node right;
Node down;
};
  
  
  
  
static Node constructList(int array[][], int i, int j, int m, int n)
  
{
  
//TO test boundary conditions
if (i > n - 1 || j > m - 1)
return null;
  
// create a new node for current i and j
// and recursively allocate its down and
// right pointers
Node temp = new Node();
temp.data = array[i][j];
temp.right = constructList(array, i, j + 1, m, n);
temp.down = constructList(array, i + 1, j, m, n);
return temp;
}
  
  
  
// function to display the matrix
static void displayMatrix(Node head)
  
{
  
// pointer to move right
Node Right;
// pointer to move down
Node Down = head;
  
// loop till node->down is not NULL
  
while (Down != null)
  
{
Right = Down;
  
// loop till node->right is not NULL
  
while (Right != null)
{
System.out.print(Right.data + " ");
  
Right = Right.right;
}
  
System.out.println();
  
Down = Down.down;
}
}
  
  
  
// main driver program
public static void main(String args[]) throws FileNotFoundException
  
{
// 2D matrix 3*3 matrix
   // read from file
   File input1 =new File("C:\\Users\\CHITTIMALLA\\Desktop\\input.txt");
   Scanner sc=new Scanner(input1);
  
  
  
  
int[][] arr = new int[3][3];
// store into array
for(int i=0;i<3;i++)
   for(int j=0;j<3;j++)
       arr[i][j]=sc.nextInt();
  
int m = 3;
int n = 3;
  
Node head = constructList(arr, 0, 0, m, n);
System.out.println("The matrix is : ");
displayMatrix(head);
}
  
  
  
  
  
}

Input file:

Output: