Compilare: user.cpp: In function ‘int main()’: user.cpp:31:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<bands.size()-1;i++) ^ user.cpp:23:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&N,&M); ^ user.cpp:26:53: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%lf %lf",&P[i].first,&P[i].second); ^ user.cpp:53:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%lf%lf",&x,&y); ^