Sort the given matrix - GeeksforGeeks

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

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

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.

C++

// C++ implementation to sort the given matrix 
#include <bits/stdc++.h> 
using namespace std; 
  
#define SIZE 10 
  
// function to sort the given matrix 
void sortMat(int mat[SIZE][SIZE], int n) 
{ 
    // temporary matrix of size n^2 
    int temp[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[] 
    sort(temp, temp + k); 
      
    // 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 
void printMat(int mat[SIZE][SIZE], int n) 
{ 
    for (int i = 0; i < n; i++) { 
        for (int j = 0; j < n; j++) 
            cout << mat[i][j] << " "; 
        cout << endl; 
    } 
} 
  
// Driver program to test above 
int main() 
{ 
    int mat[SIZE][SIZE] = { { 5, 4, 7 }, 
                            { 1, 3, 8 }, 
                            { 2, 9, 6 } }; 
    int n = 3; 
  
    cout << "Original Matrix:\n"; 
    printMat(mat, n); 
  
    sortMat(mat, n); 
  
    cout << "\nMatrix After Sorting:\n"; 
    printMat(mat, n); 
  
    return 0; 
} 

Java

// Java implementation to  
// sort the given matrix 
import 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. 

Python3

# Python3 implementation to sort 
# the given matrix 
  
SIZE = 10
  
# Function to sort the given matrix 
def sortMat(mat, n) : 
      
    # Temporary matrix of size n^2 
    temp = [0] * (n * n) 
    k = 0
  
    # Copy the elements of matrix   
    # one by one into temp[] 
    for i in range(0, n) : 
          
        for j in range(0, n) : 
              
            temp[k] = mat[i][j] 
            k += 1
  
    # sort temp[] 
    temp.sort() 
      
    # copy the elements of temp[]  
    # one by one in mat[][] 
    k = 0
      
    for i in range(0, n) : 
          
        for j in range(0, n) : 
            mat[i][j] = temp[k] 
            k += 1
  
  
# Function to print the given matrix 
def printMat(mat, n) : 
      
    for i in range(0, n) : 
          
        for j in range( 0, n ) : 
              
            print(mat[i][j] , end = " ") 
              
        print() 
      
      
# Driver program to test above 
mat = [ [ 5, 4, 7 ], 
        [ 1, 3, 8 ], 
        [ 2, 9, 6 ] ] 
n = 3
  
print( "Original Matrix:") 
printMat(mat, n) 
  
sortMat(mat, n) 
  
print("\nMatrix After Sorting:") 
printMat(mat, n) 
  
  
# This code is contributed by Nikita Tiwari. 

C#

// C# implementation to 
// sort the given matrix 
using System; 
  
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[] 
        Array.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++) 
            Console.Write(mat[i, j] + " "); 
            Console.WriteLine(); 
        } 
    } 
  
    // Driver code 
    public static void Main() 
    { 
        int[, ] mat = { { 5, 4, 7 }, 
                        { 1, 3, 8 }, 
                        { 2, 9, 6 } }; 
        int n = 3; 
  
        Console.WriteLine("Original Matrix:"); 
        printMat(mat, n); 
  
        sortMat(mat, n); 
  
        Console.WriteLine("Matrix After Sorting:"); 
        printMat(mat, n); 
    } 
} 
  
// This code is contributed by Sam007 

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).

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My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

Python3

C#

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