Compilare: user.cpp: In function ‘void add_edges()’: user.cpp:94:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j; ^ user.cpp:94:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp: In function ‘int main()’: user.cpp:161:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("elicoptere.in","r",stdin); ^ user.cpp:162:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("elicoptere.out","w",stdout); ^ user.cpp:164:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &op, &n, &k); ^ user.cpp: In member function ‘void Point::read()’: user.cpp:32:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &x, &y); ^