Write a Program to Check if Two Matrices Are Equal in C

Matrices are commonly used in programming for various calculations and data manipulation tasks. In this post, we’ll explore how to write a C program to check if two matrices are equal. Two matrices are considered equal if they have the same dimensions and identical elements in corresponding positions.

1. Understanding Matrix Equality

To check if two matrices are equal, we need to verify the following conditions:

• The dimensions of both matrices should be the same (i.e., same number of rows and columns).
• Each element in one matrix must be the same as the corresponding element in the other matrix.

2. Writing the Program

Let’s write the C program to check if two matrices are equal.

Program to Check if Two Matrices Are Equal

#include <stdio.h>

int main() {
    int rows, cols;
    int matrix1[10][10], matrix2[10][10];
    int areEqual = 1; // Flag to track if matrices are equal

    // Input the dimensions of the matrices
    printf("Enter the number of rows and columns: ");
    scanf("%d %d", &rows, &cols);

    // Input elements of the first matrix
    printf("Enter elements of the first matrix:
");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("Element at [%d][%d]: ", i, j);
            scanf("%d", &matrix1[i][j]);
        }
    }

    // Input elements of the second matrix
    printf("Enter elements of the second matrix:
");
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            printf("Element at [%d][%d]: ", i, j);
            scanf("%d", &matrix2[i][j]);
        }
    }

    // Compare the two matrices
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            if (matrix1[i][j] != matrix2[i][j]) {
                areEqual = 0;
                break;
            }
        }
        if (!areEqual) break;
    }

    // Print result
    if (areEqual) {
        printf("The matrices are equal.
");
    } else {
        printf("The matrices are not equal.
");
    }

    return 0;
}

Explanation of the Code

Here’s how the program works:

• First, the program asks the user to input the dimensions of the matrices and ensures that both matrices have the same number of rows and columns.
• Then, the user enters the elements of the two matrices, which are stored in the arrays matrix1 and matrix2.
• The program then uses a nested for loop to compare each corresponding element of the matrices. If any pair of elements differs, the program sets the flag areEqual to 0 and breaks out of the loop.
• If the matrices are found to be equal, the program prints "The matrices are equal." Otherwise, it prints "The matrices are not equal."

3. Example Output

Here’s an example of the program in action:

Enter the number of rows and columns: 2 2
Enter elements of the first matrix:
Element at [0][0]: 1
Element at [0][1]: 2
Element at [1][0]: 3
Element at [1][1]: 4
Enter elements of the second matrix:
Element at [0][0]: 1
Element at [0][1]: 2
Element at [1][0]: 3
Element at [1][1]: 5

The matrices are not equal.
  

4. Common Mistakes to Avoid

Here are a few common mistakes to avoid when checking matrix equality:

• Different Dimensions: Ensure both matrices have the same dimensions. If they don’t, matrix equality is impossible.
• Array Indexing Errors: Be careful with your array indices when accessing elements in the matrices.

5. Conclusion

In this post, we’ve written a C program to check if two matrices are equal. Matrix equality requires both the dimensions and the elements of the matrices to match. Understanding matrix operations is important in various applications like computer graphics, machine learning, and more.

By practicing matrix equality and other matrix-based operations, you’ll improve your problem-solving skills and gain a deeper understanding of data manipulation in C programming.