Compilare: user.cpp: In function ‘int main()’: user.cpp:70:10: warning: statement has no effect [-Wunused-value] for(i; i>=0; --i) ^ user.cpp:27:13: warning: unused variable ‘cnt’ [-Wunused-variable] int a,b,cnt=0; ^ user.cpp:28:10: warning: unused variable ‘pas’ [-Wunused-variable] bool pas=false; ^ user.cpp:32:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&a,&b); ^