Compilare: user.cpp: In function ‘int main()’: user.cpp:6:9: warning: unused variable ‘i’ [-Wunused-variable] int i,t,a,b,l; ^ user.cpp:9:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d" ,&t); ^ user.cpp:19:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d" ,&a,&b); ^