matrix.c

#include <stdio.h>
#include <stdlib.h>

void printMatrix(double** m, int n) {
  printf("\n\n");
  int i = 0;
  int j = 0;

  for (i = 0; i < n; i++) {
    for (j = 0; j < n - 1; j++) {
      printf("%lf ", m[i][j]);
    }
    printf("%lf\n", m[i][n - 1]);
  }
  printf("\n");
}
int main(void) {
  int n;
  int** A;
  int** B;


  int i = 0;
  int j = 0;

  // input foramt:
  // 1st line 1 number N = dim(A) = dim(B) = dim(C)
  // then N lines of N numbers separated by space for A
  // then N lines of N numbers separated by space for B
  printf("Please enter matrix dimension n : ");
  scanf("%d", &n);

  // allocate memory for the matrices

  // note that for each matrix there
  // are only two memory allocations

  ///////////////////// Matrix A //////////////////////////
  A = (int**)malloc(n * sizeof(int*));
  A[0] = (int*)malloc(n * n * sizeof(int));
  if (!A) {
    printf("memory failed \n");
    exit(1);
  }
  for (i = 1; i < n; i++) {
    A[i] = A[0] + i * n;
    if (!A[i]) {
      printf("memory failed \n");
      exit(1);
    }
  }
  ///////////////////// Matrix B //////////////////////////

  B = (int**)malloc(n * sizeof(int*));
  B[0] = (int*)malloc(n * n * sizeof(int));
  if (!B) {
    printf("memory failed \n");
    exit(1);
  }
  for (i = 1; i < n; i++) {
    B[i] = B[0] + i * n;
    if (!B[i]) {
      printf("memory failed \n");
      exit(1);
    }
  }


  // initialize the matrices
  // we can also create random matrices using the rand() method from the
  // math.h library
  for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) {
      int d1 = rand()%99;
      int d2 = rand()%99;
      A[i][j] = d1;
      B[i][j] = d2;
    }
  }


  printMatrix(A, n);
  printMatrix(B, n);

  // deallocate memory
  free(A[0]);
  free(A);
  free(B[0]);
  free(B);

  return 0;
}