Compilare: user.cpp: In function ‘void bfs()’: user.cpp:128:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < v [poz] . size () ; ++ i ) ~~^~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘int getbuff()’: user.cpp:30:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff , 1 , NM2 , stdin ); ^ user.cpp:41:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff , 1 , NM2 , stdin ); ^ user.cpp: In function ‘int position(int)’: user.cpp:111:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:140:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (in , "r" , stdin); ^ user.cpp:141:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen (out , "w" , stdout); ^ user.cpp:142:35: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (buff , 1 , NM2 , stdin); ^