Compilare: user.cpp: In function ‘int main()’: user.cpp:27:9: warning: unused variable ‘i’ [-Wunused-variable] int i, x, y, z; ^ user.cpp:27:12: warning: unused variable ‘x’ [-Wunused-variable] int i, x, y, z; ^ user.cpp:27:15: warning: unused variable ‘y’ [-Wunused-variable] int i, x, y, z; ^ user.cpp:27:18: warning: unused variable ‘z’ [-Wunused-variable] int i, x, y, z; ^ user.cpp:25:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alge.in", "r", stdin); ^ user.cpp:26:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("alge.out", "w", stdout); ^