Compilare: user.cpp: In function ‘void read()’: user.cpp:28:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<strlen(aux); i++) ^ user.cpp:22:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ user.cpp:24:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(aux, 1, sizeof(aux), stdin); ^