Step by Step solution about How to resolve the algorithm Identity matrix step by step in the C programming language

This C program generates and prints an identity matrix of a given size. An identity matrix is a square matrix with 1s on the main diagonal and 0s everywhere else.

1. Header Files:

   • The program includes the necessary header files:
     • <stdlib.h> for dynamic memory allocation and exit statuses.
     • <stdio.h> for input and output functions.

2. Main Function:

   • The main function is the entry point of the program. It takes two command-line arguments:
     • argc is the count of arguments passed to the program.
     • argv is an array of strings containing the arguments.

3. Input Validation:

   • The program checks if the user provided the correct number of arguments. If less than 2 arguments are given, it prints an error message and exits.

4. Row Size:

   • It parses the first command-line argument (argv[1]) into an integer and stores it in rowsize. This value represents the number of rows and columns in the identity matrix.

5. Dimension Validation:

   • The program checks if rowsize is negative. If it is, it prints an error message and exits because the dimensions of a matrix cannot be negative.

6. Number of Elements:

   • It calculates the number of elements in the matrix as numElements = rowsize * rowsize. It checks for integer overflow by comparing numElements with rowsize. If overflow occurs, it prints an error message and aborts.

7. Memory Allocation:

   • It allocates memory for the matrix using calloc, which sets all allocated memory to 0.
   • It allocates an array of numElements pointers to integers, which will store the rows of the matrix.
   • For each row, it allocates an array of numElements integers using calloc again.

8. Identity Matrix Creation:

   • The program iterates over each row and assigns 1 to the element on the main diagonal (matrix[row][row]).

9. Printing the Matrix:

   • It prints the generated identity matrix to the console. It iterates over each row and column and prints the elements separated by spaces.

10. Cleanup:

• The program does not explicitly deallocate the allocated memory, relying on the operating system to do so when the program exits.

#include <stdlib.h>
#include <stdio.h>
int main(int argc, char** argv) {
   if (argc < 2) {
      printf("usage: identitymatrix <number of rows>\n");
      exit(EXIT_FAILURE);
   }
   int rowsize = atoi(argv[1]);
   if (rowsize < 0) {
      printf("Dimensions of matrix cannot be negative\n");
      exit(EXIT_FAILURE);
   }
   int numElements = rowsize * rowsize;
   if (numElements < rowsize) {
      printf("Squaring %d caused result to overflow to %d.\n", rowsize, numElements);
      abort();
   }
   int** matrix = calloc(numElements, sizeof(int*));
   if (!matrix) {
      printf("Failed to allocate %d elements of %ld bytes each\n", numElements, sizeof(int*));
      abort();
   }
   for (unsigned int row = 0;row < rowsize;row++) {
      matrix[row] = calloc(numElements, sizeof(int));
      if (!matrix[row]) {
         printf("Failed to allocate %d elements of %ld bytes each\n", numElements, sizeof(int));
         abort();
      }
      matrix[row][row] = 1;
   }
   printf("Matrix is: \n");
   for (unsigned int row = 0;row < rowsize;row++) {
      for (unsigned int column = 0;column < rowsize;column++) {
         printf("%d ", matrix[row][column]);
      }
      printf("\n");
   }
}