Given a n x n matrix. The problem is to sort the matrix row-wise and column wise.
Examples:
Input : mat[][] = { {4, 1, 3}, {9, 6, 8}, {5, 2, 7} } Output : 1 3 4 2 5 7 6 8 9 Input : mat[][] = { {12, 7, 1, 8}, {20, 9, 11, 2}, {15, 4, 5, 13}, {3, 18, 10, 6} } Output : 1 5 8 12 2 6 10 15 3 7 11 18 4 9 13 20
Approach: Following are the steps:
- Sort each row of the matrix.
- Get transpose of the matrix.
- Again sort each row of the matrix.
- Again get transpose of the matrix.
Algorithm for getting transpose of the matrix:
for (int i = 0; i < n; i++) { for (int j = i + 1; i < n; i++) { int temp = mat[i][j]; mat[i][j] = mat[j][i]; mat[j][i] = temp; } }
Java
// Java implementation to sort the // matrix row-wise and column-wise import java.util.Arrays; class GFG { static final int MAX_SIZE= 10 ; // function to sort each row of the matrix static void sortByRow( int mat[][], int n) { for ( int i = 0 ; i < n; i++) // sorting row number 'i' Arrays.sort(mat[i]); } // function to find transpose of the matrix static void transpose( int mat[][], int n) { for ( int i = 0 ; i < n; i++) for ( int j = i + 1 ; j < n; j++) { // swapping element at index (i, j) // by element at index (j, i) int temp=mat[i][j]; mat[i][j]=mat[j][i]; mat[j][i]=temp; } } // function to sort the matrix row-wise // and column-wise static void sortMatRowAndColWise( int mat[][], int n) { // sort rows of mat[][] sortByRow(mat, n); // get transpose of mat[][] transpose(mat, n); // again sort rows of mat[][] sortByRow(mat, n); // again get transpose of mat[][] transpose(mat, n); } // function to print the 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 code public static void main (String[] args) { int mat[][] = { { 4 , 1 , 3 }, { 9 , 6 , 8 }, { 5 , 2 , 7 } }; int n = 3 ; System.out.print("Original Matrix: "); printMat(mat, n); sortMatRowAndColWise(mat, n); System.out.print(" Matrix After Sorting: "); printMat(mat, n); } } // This code is contributed by Anant Agarwal. |
Output:
Original Matrix: 4 1 3 9 6 8 5 2 7 Matrix After Sorting: 1 3 4 2 5 7 6 8 9
Time Complexity: O(n2log2n).
Auxiliary Space: O(1).
Please refer complete article on Sort the matrix row-wise and column-wise for more details!
Ready to dive in? Explore our Free Demo Content and join our DSA course, trusted by over 100,000 neveropen!