Compilare: user.cpp: In function ‘int main()’: user.cpp:23:11: warning: unused variable ‘x’ [-Wunused-variable] int N,x,y,sol; ^ user.cpp:23:13: warning: unused variable ‘y’ [-Wunused-variable] int N,x,y,sol; ^ user.cpp:24:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("heavymetal.in","r",stdin); ^ user.cpp:25:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("heavymetal.out","w",stdout); ^ user.cpp:26:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:29:38: 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); ^