Compilare: user.cpp: In function ‘int bfs()’: user.cpp:22:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<L[a].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:45:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<L[a].size();j++){ ^ user.cpp:68:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<L[d].size();i++){ ^ user.cpp:36:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&m,&k); ^ user.cpp:38:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&a,&b); ^