Compilare: user.cpp: In function ‘int main()’: user.cpp:57:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pav.in", "r", stdin); ^ user.cpp:58:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pav.out", "w", stdout); ^ user.cpp:60:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:61:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &missing.first, &missing.second); ^ user.cpp: In function ‘void divide(int, int, int, int, std::pair<int, int>, int)’: user.cpp:46:4: warning: ‘nr’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(k!=nr) ^