Compilare: user.cpp: In function ‘int main()’: user.cpp:5: warning: unused variable ‘a’ user.cpp:5: warning: unused variable ‘x’ user.cpp:5: warning: unused variable ‘y’ user.cpp:5: warning: unused variable ‘y1’ user.cpp:5: warning: unused variable ‘x2’ user.cpp:5: warning: unused variable ‘y2’ user.cpp:5: warning: unused variable ‘j’ user.cpp:5: warning: unused variable ‘i’ user.cpp:5: warning: unused variable ‘p’ user.cpp:7: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result