Given a n x n matrix. The problem is to sort the given matrix in strict order. Here strict order means that matrix is sorted in a way such that all elements in a row are sorted in increasing order and for row ‘i’, where 1 <= i <= n-1, first element of row ‘i’ is greater than or equal to the last element of row ‘i-1’.
Examples:
Input : mat[][] = { {5, 4, 7},
{1, 3, 8},
{2, 9, 6} }
Output : 1 2 3
4 5 6
7 8 9
Approach: Create a temp[] array of size n^2. Starting with the first row one by one copy the elements of the given matrix into temp[]. Sort temp[]. Now one by one copy the elements of temp[] back to the given matrix.
Java
// Java implementation to // sort the given matriximport java.io.*;import java.util.*; class GFG { static int SIZE = 10; // function to sort the given matrix static void sortMat(int mat[][], int n) { // temporary matrix of size n^2 int temp[] = new int[n * n]; int k = 0; // copy the elements of matrix // one by one into temp[] for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) temp[k++] = mat[i][j]; // sort temp[] Arrays.sort(temp); // copy the elements of temp[] // one by one in mat[][] k = 0; for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) mat[i][j] = temp[k++]; } // function to print the given matrix static void printMat(int mat[][], int n) { for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) System.out.print( mat[i][j] + " "); System.out.println(); } } // Driver program to test above public static void main(String args[]) { int mat[][] = { { 5, 4, 7 }, { 1, 3, 8 }, { 2, 9, 6 } }; int n = 3; System.out.println("Original Matrix:"); printMat(mat, n); sortMat(mat, n); System.out.println("Matrix After Sorting:"); printMat(mat, n); }} // This code is contributed by Nikita Tiwari. |
Output:
Original Matrix: 5 4 7 1 3 8 2 9 6 Matrix After Sorting: 1 2 3 4 5 6 7 8 9
Time Complexity: O(n2log2n).
Auxiliary Space: O(n2).
Please refer complete article on Sort the given matrix for more details!