Compilare: main.cpp: In function 'void bfs(int)': main.cpp:12:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[a].size();i++) { ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:30:38: 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 ,&x); ^ main.cpp:32:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d" ,&a ,&b); ^