Compilare: user.cpp: In function ‘int main()’: user.cpp:47:26: warning: argument to ‘sizeof’ in ‘void* memset(void*, int, size_t)’ call is the same expression as the destination; did you mean to dereference it? [-Wsizeof-pointer-memaccess] memset(v + r, 1, sizeof(v + r)); ^ user.cpp:39:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d%d%d%d", &n, &m, &r, &c); ^ user.cpp:42:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &a[j][i]); ^