Compilare: user.cpp: In function ‘int main()’: user.cpp:53:13: warning: unused variable ‘x’ [-Wunused-variable] int x , y; ^ user.cpp:53:17: warning: unused variable ‘y’ [-Wunused-variable] int x , y; ^ user.cpp:61:13: warning: unused variable ‘x’ [-Wunused-variable] int x , y , xx , yy; ^ user.cpp:61:17: warning: unused variable ‘y’ [-Wunused-variable] int x , y , xx , yy; ^ user.cpp:61:21: warning: unused variable ‘xx’ [-Wunused-variable] int x , y , xx , yy; ^ user.cpp:61:26: warning: unused variable ‘yy’ [-Wunused-variable] int x , y , xx , yy; ^ user.cpp:47:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nn.in","r",stdin); ^ user.cpp:48:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nn.out","w",stdout); ^ user.cpp:50:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:54:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &v[i].x, &v[i].y); ^ user.cpp:62:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a.x, &a.y); ^ user.cpp:63:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &b.x, &b.y); ^