Compilare: user.cpp: In function ‘int main(int, const char**)’: user.cpp:97:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < pth.size(); i ++ ) { ^ user.cpp:100:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int j = 0; j < pth[i].size(); j ++ ) { ^ user.cpp: In function ‘void dfs(int, int)’: user.cpp:31:25: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] if( y == f || y == pos ) ^