Compilare: user.cpp:15:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main() ^ user.cpp: In function ‘int main()’: user.cpp:20:9: warning: unused variable ‘i’ [-Wunused-variable] int x,y,i,k; ^ user.cpp:20:11: warning: unused variable ‘k’ [-Wunused-variable] int x,y,i,k; ^ user.cpp:22:20: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d ", &x); ^ user.cpp:23:20: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d ", &y); ^