C Program To Check whether Matrix is Skew Symmetric or not

Difficulty Level : Basic
Last Updated : 29 Nov, 2020

A Skew Symmetric Matrix or Anti-Symmetric Matrix is a square matrix whose transpose is negative to that of the original matrix. If the entry in the i^th row and j^th column of a matrix is a[i][j], i.e. if A = (a[i][j]) then the skew symmetric condition is -A = -a[j][i].
Examples :

Input : matrix:     0   5  -4          
                   -5   0   1                            
                    4  -1   0                            

Output:  
Transpose matrix:   0  -5   4
                    5   0  -1
                   -4   1   0
Skew Symmetric matrix

Steps:

Find the transpose of the input matrix.
If the input matrix is equal to the negative of its transpose matrix, then the matrix is Skew Symmetrical.

Java

// java program to check
// whether given matrix
// is skew-symmetric or not
import java.io.*;
 
class GFG {
     
static int ROW =3;
static int COL =3;
 
// Utility function to create transpose matrix
 static void transpose(int transpose_matrix[][],
                        int matrix[][])
{
for (int i = 0; i < ROW; i++)
    for (int j = 0; j < COL; j++)
        transpose_matrix[j][i] = matrix[i][j];
}
 
// Utility function to check skew - symmetric
// matrix condition
 static boolean check(int transpose_matrix[][],
                    int matrix[][])
{
    for (int i = 0; i < ROW; i++)
        for (int j = 0; j < COL; j++)
            if (matrix[i][j] != -transpose_matrix[i][j])
                return false;
    return true;
}
 
// Utility function to print a matrix
 static void printMatrix(int matrix[][])
{
    for (int i = 0; i < ROW; i++)
    {
    for (int j = 0; j < COL; j++)
            System.out.print(matrix[i][j] + " ");
    System.out.println();
    }
}
 
// Driver program to test above functions
public static void main (String[] args) {
        int matrix[][] = {
                            {0, 5, -4},
                            {-5, 0, 1},
                            {4, -1, 0},
                        };
 
    int transpose_matrix[][] = new int[ROW][COL];
 
    // Function create transpose matrix
    transpose(transpose_matrix, matrix);
 
    System.out.println ("Transpose matrix: ");
    printMatrix(transpose_matrix);
 
    // Check whether matrix is skew-symmetric or not
    if (check(transpose_matrix, matrix))
    System.out.println("Skew Symmetric Matrix");
    else
    System.out.println("Not Skew Symmetric Matrix");
 
         
    }
}
 
// This code is contributed by vt_m.

C++

// C program to check whether given matrix
// is skew-symmetric or not
#include <stdio.h>
#include <stdlib.h>
 
#define ROW 3
#define COL 3
 
// Utility function to create transpose matrix
void transpose(int transpose_matrix[ROW][COL],
                         int matrix[ROW][COL])
{
   for (int i = 0; i < ROW; i++)
      for (int j = 0; j < COL; j++)
         transpose_matrix[j][i] = matrix[i][j];
}
 
// Utility function to check skew - symmetric
// matrix condition
bool check(int transpose_matrix[ROW][COL],
                    int matrix[ROW][COL])
{
    for (int i = 0; i < ROW; i++)
        for (int j = 0; j < COL; j++)
            if (matrix[i][j] != -transpose_matrix[i][j])
                return false;
    return true;
}
 
// Utility function to print a matrix
void printMatrix(int matrix[ROW][COL])
{
    for (int i = 0; i < ROW; i++)
    {
       for (int j = 0; j < COL; j++)
            printf("%d ", matrix[i][j]);
       printf("\n");
    }
}
 
// Driver program to test above functions
int main()
{
    int matrix[ROW][COL] = {
                            {0, 5, -4},
                            {-5, 0, 1},
                            {4, -1, 0},
                           };
 
    int transpose_matrix[ROW][COL];
 
    // Function create transpose matrix
    transpose(transpose_matrix, matrix);
 
    printf ("Transpose matrix: \n");
    printMatrix(transpose_matrix);
 
    // Check whether matrix is skew-symmetric or not
    if (check(transpose_matrix, matrix))
       printf("Skew Symmetric Matrix");
    else
       printf("Not Skew Symmetric Matrix");
 
    return 0;
}

C#

// C# program to check
// whether given matrix
// is skew-symmetric or not
using System;
 
class GFG 
{
static int ROW =3;
static int COL =3;
 
// Utility function to
// create transpose matrix
static void transpose(int [,]transpose_matrix,
                      int [,]matrix)
{
for (int i = 0; i < ROW; i++)
    for (int j = 0; j < COL; j++)
        transpose_matrix[j,i] = matrix[i,j];
}
 
// Utility function to check 
// skew - symmetric matrix 
// condition
static bool check(int [,]transpose_matrix,
                  int [,]matrix)
{
    for (int i = 0; i < ROW; i++)
        for (int j = 0; j < COL; j++)
            if (matrix[i, j] != 
                -transpose_matrix[i, j])
                return false;
    return true;
}
 
// Utility function
// to print a matrix
static void printMatrix(int [,]matrix)
{
    for (int i = 0; i < ROW; i++)
    {
    for (int j = 0; j < COL; j++)
            Console.Write(matrix[i, j] + 
                                   " ");
    Console.WriteLine();
    }
}
 
// Driver Code
public static void Main () 
{
    int [,]matrix = {{0, 5, -4},
                     {-5, 0, 1},
                     {4, -1, 0},};
 
    int [,]transpose_matrix = new int[ROW, COL];
 
    // Function create transpose matrix
    transpose(transpose_matrix, matrix);
 
    Console.WriteLine("Transpose matrix: ");
    printMatrix(transpose_matrix);
 
    // Check whether matrix is
    // skew-symmetric or not
    if (check(transpose_matrix, matrix))
    Console.WriteLine("Skew Symmetric Matrix");
    else
    Console.WriteLine("Not Skew Symmetric Matrix");
    }
}
 
// This code is contributed by anuj_67.

Python3

# Python 3 program to check
# whether given matrix
# is skew-symmetric or not
ROW=3
COL=3
 
# Utility function to
# create transpose matrix
def transpose(transpose_matrix,matrix):
    for i in range (ROW):
        for j in range(COL):
            transpose_matrix[j][i] = matrix[i][j]
             
# Utility function to
# check skew - symmetric
# matrix condition
def check(transpose_matrix,matrix):
    for i in range(ROW):
        for j in range(COL):
            if (matrix[i][j] != -transpose_matrix[i][j]):
                return False
    return True
     
# Utility function to print a matrix
def printMatrix(matrix):
    for i in range (ROW):
        for j in range(COL):
            print(matrix[i][j]," ",end="")
        print()
         
# Driver program to test above functions
matrix= [
            [0, 5, -4],
            [-5, 0, 1],
            [4, -1, 0],
        ]
transpose_matrix=[[0 for i in range(3)] for j in range(3)]
 
# Function create transpose matrix
transpose(transpose_matrix, matrix)
print("Transpose matrix:")
printMatrix(transpose_matrix)
 
# Check whether matrix is
# skew-symmetric or not
if (check(transpose_matrix, matrix)):
    print("Skew Symmetric Matrix")
else:
    print("Not Skew Symmetric Matrix")
 
# This code is contributed
# by Azkia Anam.

Output

Transpose matrix: 
0 -5 4 
5 0 -1 
-4 1 0 
Skew Symmetric Matrix

References : Wikipedia
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