Compilare: main.cpp: In function 'int BFS(int, int)': main.cpp:56:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < G[node].size(); ++i ) { ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:129:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int k = 0; k < v.size(); ++k ) { ~~^~~~~~~~~~ main.cpp: In function 'char readChar()': main.cpp:72:34: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread( rbuf, 1, 131072, fin ); ^