Compilare: main.cpp: In function 'void bfs(int)': main.cpp:26:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i =0;i<G[act.first].size();++i) ~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:39:44: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %d", &n, &m, &start); ^ main.cpp:42:35: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d",&x,&y); ^