Compilare: user.cpp: In function ‘void BFS(int)’: user.cpp:67:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x].size();++i) ^ user.cpp: In function ‘int getInt()’: user.cpp:106:67: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++cnt >= buffer) fread(buff, buffer, 1, stdin), cnt = 0; ^ user.cpp:110:67: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++cnt >= buffer) fread(buff, buffer, 1, stdin), cnt = 0; ^ user.cpp: In function ‘int main()’: user.cpp:118:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("unlock.in","r",stdin); ^ user.cpp:119:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("unlock.out","w",stdout); ^