Compilare: user.c: In function ‘main’: user.c:20:2: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] int (*c)[m] = malloc(sizeof(int[n][m])); ^ user.c:20:16: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] int (*c)[m] = malloc(sizeof(int[n][m])); ^ user.c:7:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d\n", &m, &n); ^ user.c:11:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d ", &a[i]); ^ user.c:13:8: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "\n"); ^ user.c:15:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d ", &b[j]); ^