C Program to check Matrix is an Identity Matrix

How to write a C Program to check whether Matrix is an Identity Matrix or not with example. An Identity Matrix is a square matrix whose main diagonal elements are ones, and all the other elements are zeros.

C Program to check Matrix is an Identity Matrix Example

This program allows the user to enter the number of rows and columns of a Matrix. Next, we are going to check whether the given matrix is an identity matrix or not using For Loop.

 #include<stdio.h>
 
int main()
{
 	int i, j, rows, columns, a[10][10], Flag = 1;
  
 	printf("\n Please Enter Number of rows and columns  :  ");
 	scanf("%d %d", &i, &j);
 
 	printf("\n Please Enter the Matrix Elements \n");
 	for(rows = 0; rows < i; rows++)
  	{
   		for(columns = 0; columns < j; columns++)
    	{
      		scanf("%d", &a[rows][columns]);
    	}
  	}
     
 	for(rows = 0; rows < i; rows++)
  	{
   		for(columns = 0; columns < j; columns++)
    	{
    		if(a[rows][columns] != 1 && a[columns][rows] != 0)
    		{
    			Flag = 0;
    			break;
			}
   	 	}
  	}
  	if(Flag == 1)
  	{
  		printf("\n The Matrix that you entered is an Identity Matrix ");
	}
	else
	{
		printf("\n The Matrix that you entered is Not an Identity Matrix ");
	}
  	
 	return 0;
}

Program to check Matrix is an Identity Matrix or Not 1

In this Program to check Matrix is an Identity Matrix, We declared single Two dimensional arrays Multiplication of size of 10 * 10.

Below C Programming statements asks the User to enter the Matrix size (Number of rows and columns. For instance 2 Rows, 2 Columns = a[2][2] )

printf("\n Please Enter Number of rows and columns  :  ");
scanf("%d %d", &i, &j);

Next, we used for loop to iterate each item present in a[2][2] matrix. Conditions inside the C for loops ((rows < i) and (columns < j)) will ensure the compiler, not to exceed the matrix limit. Otherwise, the C two dimensional array will overflow. The scanf statement inside the for loop will store the user entered values in every individual array element such as a[0][0], a[0][1], …..

for(rows = 0; rows < i; rows++).
{
  for(columns = 0; columns < j; columns++)
   {
     scanf("%d", &a[rows][columns]);
   }
}

In the next line, We have one more for loop to check the matrix is an identity matrix or not

for(rows = 0; rows < i; rows++)
{
   	for(columns = 0; columns < j; columns++)
    	{
    		if(a[rows][columns] != 1 && a[columns][rows] != 0)
    		{
    			Flag = 0;
    			break;
		}
   	}
}

Let me try the program with other values

 Please Enter Number of rows and columns  :  3 3

 Please Enter the Matrix Elements 
1 0 0
0 1 0
0 1 1

 The Matrix that you entered is Not an Identity Matrix

C Program to check Matrix is an Identity Matrix Example 2

This C program is similar to the above example. But, this time, we are using the C Else If Statement instead of C If else Statement.

 #include<stdio.h>
 
int main()
{
 	int i, j, rows, columns, a[10][10], Flag = 1;
  
 	printf("\n Please Enter Number of rows and columns  :  ");
 	scanf("%d %d", &i, &j);
 
 	printf("\n Please Enter the Matrix Elements \n");
 	for(rows = 0; rows < i; rows++)
  	{
   		for(columns = 0;columns < j;columns++)
    	{
      		scanf("%d", &a[rows][columns]);
    	}
  	}
     
 	for(rows = 0; rows < i; rows++)
  	{
   		for(columns = 0; columns < j; columns++)
    	{
    		if(rows == columns && a[rows][columns] != 1)
    		{
    			Flag = 0;
			}
			else if(rows != columns && a[rows][columns] != 0)
			{
				Flag = 0;
			}
   	 	}
  	}
  	if(Flag == 1)
  	{
  		printf("\n The Matrix that you entered is an Identity Matrix ");
	}
	else
	{
		printf("\n The Matrix that you entered is Not an Identity Matrix ");
	}
  	
 	return 0;
}

Identity matrix output

 Please Enter Number of rows and columns  :  3 3

 Please Enter the Matrix Elements 
1 0 0
0 1 0
0 0 1

 The Matrix that you entered is an Identity Matrix

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