Question

Program to determine whether a given matrix is an identity matrix.
A matrix is said to be the identity matrix if it is the square matrix in which elements of principle diagonal are ones, and the rest of the elements are zeroes.

[1,     0,     0]
[0,     1,     0]
[0,     0,     1]

MATRIX IS AN IDENTITY MATRIX

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Code

Java

Python

Java

import java.util.Scanner;
public class identityMatrix
{
    public static void main(String[] args)
    {
        int size=0,i=0,j=0;
        int a[][];
        boolean flag=true;

        Scanner sc=new Scanner(System.in);
        System.out.println("ENTER THE SIZE OF MATRIX");
        size=sc.nextInt();

        a=new int[size][size];
        System.out.println("ENTER THE ELEMENTS IN MATRIX");
        for(i=0;i< size;i++)
        {
            for(j=0;j< size;j++)
            {
                System.out.print("("+(i+1)+","+(j+1)+"):");
                a[i][j]=sc.nextInt();
            }
        }

        System.out.println("MATRIX:");
        for(i=0;i< size;i++)
        {
            for(j=0;j< size;j++)
            {
                System.out.print(a[i][j]+" ");
            }
            System.out.println();
        }

        for(i=0;i< size;i++)
        {
            for(j=0;j< size;j++)
            {
                if(i==j)
                {
                    if(a[i][j]!=1)
                    {
                        flag=false;
                        break;
                    }

                }
                else if(i!=j)
                {
                    if(a[i][j]!=0)
                    {
                        flag=false;
                        break;
                    }
                }

            }
        }
        if(flag==true)
        {
            System.out.println("MATRIX IS AN IDENTITY MATRIX");

        }
        else
        {
            System.out.println("MATRIX IS NOT AN IDENTITY MATRIX");
        }
    }

}

Python

import numpy as np
size=int(input("Enter size of Matrix:"))
flag=True
matrix=np.empty([size,size],dtype=np.int)
# Taking input from user
print("Enter elements in matrix:")
for i in range(0,size):
    for j in range(0,size):
        print("(",(i+1),",",(j+1),")",":",end="")
        matrix[i,j]=int(input())
#printing the matrix
print("Matrix:")
for i in range(0, size):
    print(matrix[i])
#Checking whether given Matrix is identity matrix or not
for i in range(0,size):
    for j in range(0,size):
        if(i==j):
            if(matrix[i,j]!=1):
                flag=False
                break
        elif(i!=j):
            if(matrix[i,j]!=0):
                flag=False
                break
if(flag==True):
    print("Given Matrix is Identity Matrix")
else:
    print("Given Matrix is not Identity Matrix")