Compilare: user.cpp: In function ‘int main()’: user.cpp:109:21: warning: statement has no effect [-Wunused-value] sumA-tmp.first; ^ user.cpp:64:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&N); ^ user.cpp:67:46: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d%d",&t,&people,&weight); ^