Java Program to Sort the 2D Array Across Rows
This program is used to Sort the 2D array Across rows. We will use the concept of vector to sort each row.
Vector
Vector(): Creates a default vector of the initial capacity is 10.
Vector<E> v = new Vector<E>();
Functions we will use in this:
1. removeAll(): The java.util.vector.removeAll(Collection col) method is used to remove all the elements from the vector, present in the collection specified.
Syntax:
Vector.removeAll(Vector)
2. Collections.sort(): This method is used to sort the vector.
Syntax:
Collections.sort(Vector)
3. add(): This adds up elements in the vector.
Syntax:
Vector.add(value)
4. get(): This method will get an element of Vector stored at a particular index.
Syntax:
Vector.get(element);
Algorithm:
- Traverse each row one by one.
- Add elements of Row 1 in vector v.
- Sort the vector.
- Push back the sorted elements from vector to row.
- Empty the vector by removing all elements for fresh sorting.
- Repeat the above steps until all rows are done.
Implementation:
Example
Java
// Java Program to Sort the 2D array Across Rows // Importing required libraries import java.io.*; import java.lang.*; import java.util.*; // Main class public class GFG { // Main driver method public static void main(String[] args) throws java.lang.Exception { // Custom input 2D matrix int [][] arr = { { 1 , 8 , 4 , 7 , 3 }, { 8 , 3 , 1 , 7 , 5 }, { 6 , 2 , 0 , 7 , 1 }, { 2 , 6 , 4 , 1 , 9 } }; // Display message only System.out.println( "Matrix without sorting \n" ); // Print and display the matrix before sorting // using nested for loops for ( int i = 0 ; i < 4 ; i++) { for ( int j = 0 ; j < 5 ; j++) { // Printing the matrix elements System.out.print(arr[i][j] + " " ); } // New line as we are finished with one row System.out.println(); } // New line for better readability System.out.println(); // Creating an object of Vector class Vector<Integer> v = new Vector<>(); for ( int i = 0 ; i < 4 ; i++) { for ( int j = 0 ; j < 5 ; j++) { // Adding elements of row in vector v.add(arr[i][j]); } // Elements in vector gets sorted Collections.sort(v); for ( int j = 0 ; j < 5 ; j++) { // Sorted elements are pushed back from // vector to row arr[i][j] = v.get(j); } // Elements are removed from vector for fresh // sorting v.removeAll(v); } // Display message only System.out.println( "Matrix after sorting \n" ); // Print and display the matrix after sorting // using nested for loops for ( int i = 0 ; i < 4 ; i++) { for ( int j = 0 ; j < 5 ; j++) { // Printing the matrix elements System.out.print(arr[i][j] + " " ); } // New line as we are finished with one row System.out.println(); } } } |
Output
Matrix without sorting 1 8 4 7 3 8 3 1 7 5 6 2 0 7 1 2 6 4 1 9 Matrix after sorting 1 3 4 7 8 1 3 5 7 8 0 1 2 6 7 1 2 4 6 9