Compilare: user.cpp: In function ‘int main()’: user.cpp:144:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (sol[i].size() == area) ^ user.cpp:135:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("badea.in","r",stdin); ^ user.cpp:136:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("badea.out","w",stdout); ^ user.cpp:138:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &l); ^