Compilare: user.cpp: In function ‘int main()’: user.cpp:21:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<G[i].size();j++) ^ user.cpp:23:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<G[i].size();j++){ ^ user.cpp:25:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<G[x].size();k++) ^ user.cpp:13:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d" ,&n,&m); ^ user.cpp:15:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d" ,&x,&y); ^