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C++ program to check whether the matrix is an identity matrix or not using class

Submitted by Shubh Pachori, on September 15, 2022

Problem statement

Given a matrix of integers, we to check whether it is an identity matrix or not using the class and object approach.

Example:

Input: 
Enter Matrix elements :
[0][0]: 1
[0][1]: 2
[0][2]: 3
[1][0]: 4
[1][1]: 5
[1][2]: 6
[2][0]: 7
[2][1]: 8
[2][2]: 9

Output: 
Entered Matrix :
1  2  3  
4  5  6  
7  8  9  

The matrix is not an identity matrix!

C++ code to check whether the matrix is an identity matrix or not using the class and object approach

#include <iostream>
using namespace std;

// create a class
class Matrix {
  // private data member
 private:
  int matrix[3][3];

  // public member funtions
 public:
  // getMatrix() funtion to insert matrix
  void getMatrix() {
    cout << "Enter Matrix elements :" << endl;
    for (int row = 0; row < 3; row++) {
      for (int column = 0; column < 3; column++) {
        cout << "[" << row << "][" << column << "]: ";
        cin >> matrix[row][column];
      }
    }
  }

  // identityMatrix() funtion to check whether the
  // matrix is a identity matrix or not
  void identityMatrix() {
    // initialising int type variables
    // to perform operations
    int row, column, check = 1;

    cout << "\nEntered Matrix :" << endl;

    // for loop to show the inserted matrix
    for (row = 0; row < 3; row++) {
      for (column = 0; column < 3; column++) {
        cout << matrix[row][column] << "  ";
      }
      cout << "\n";
    }

    // nested for loop to traverse the whole matrix
    for (row = 0; row < 3; row++) {
      for (column = 0; column < 3; column++) {
        // if condition to check for the one's and zero's in the matrix
        if (matrix[row][column] != 1 && matrix[row][column] != 0) {
          check = 0;
          break;
        }
      }
    }

    if (check == 1) {
      cout << "\nThe matrix is an identity matrix!" << endl;
    } else {
      cout << "\nThe matrix is not an identity matrix!" << endl;
    }
  }
};

int main() {
  // create an object
  Matrix M;

  // calling getMatrix() funtion to 
  // insert Matrix
  M.getMatrix();

  // calling identityMatrix() funtion to check 
  // the matrix whether it is an identity 
  // matrix or not
  M.identityMatrix();

  return 0;
}

Output

Enter Matrix elements :
[0][0]:1
[0][1]:0
[0][2]:0
[1][0]:0
[1][1]:1
[1][2]:0
[2][0]:0
[2][1]:0
[2][2]:1

Entered Matrix :
1  0  0  
0  1  0  
0  0  1  

The matrix is an identity matrix!

Explanation

In the above code, we have created a class Matrix, one int type 2d array data members matrix[3][3] to store the elements of the matrix, and public member functions getMatrix() and identityMatrix() to store the matrix elements and to check whether the matrix is a identity matrix or not.

In the main() function, we are creating an object M of class Matrix, reading the inputted matrix by the user using getMatrix() function, and finally calling the identityMatrix() member function to check whether the matrix is a identity matrix or not. The identityMatrix() function contains the logic to check whether the matrix is a identity matrix or not and printing the result.

C++ Class and Object Programs (Set 2) »