Compilare: user.cpp: In function ‘int main()’: user.cpp:71:11: warning: unused variable ‘i’ [-Wunused-variable] int M,i,tip,x,y; ^ user.cpp:72:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("hotel.in","r",stdin); ^ user.cpp:73:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("hotel.out","w",stdout); ^ user.cpp:74:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N,&M); ^ user.cpp:78:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &tip); ^ user.cpp:82:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x,&y); ^