mult mat

#include <stdio.h>
#include <stdlib.h>
#define MEMERR perror(""); exit(-1);

double **mkMat(int n, int m) {
  double **arr = calloc(sizeof(double*), n);
  if (arr == NULL) {
    MEMERR
  }

  for (int i = 0; i < n; i++) {
    arr[i] = calloc(sizeof(double), m);
    if (arr[i] != NULL) {
      continue;
    }
    while (i--) {
      free(arr[i]);
    }
    free(arr);
    MEMERR
  }
  return arr;
}

void printMat(double *const *const arr, int n, int m) {
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      printf("%g ", arr[i][j]);
    }
    puts("");
  }
}

void freeMat(double **arr, int n) {
  for (int i = 0; i < n; i++) {
    free(arr[i]);
  }
  free(arr);
}

void readMat(double **arr, int n, int m) {
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < m; j++) {
      scanf("%lf", &arr[i][j]);
    }
  }
}

double **multMat(double **a, double **b, int n, int m, int k) {
  double **res = mkMat(n, k);
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < k; j++) {
      double sum = 0;
      for (int it = 0; it < m; it++) {
        sum += a[i][it] * b[it][j];
      }
      res[i][j] = sum;
    }
  }

  return res;
}

int main(void) {
  int m, n, p;
  double **a = NULL, **b = NULL, **c = NULL;
  scanf("%d%d%d", &m, &n, &p);
  a = mkMat(m, n);
  b = mkMat(n, p);
  readMat(a, m, n);
  readMat(b, n, p);
  c = multMat(a, b, m, n, p);

  printMat(c, m, p);
  freeMat(a, m);
  freeMat(b, n);
  freeMat(c, m);
  return 0;
}