Compilare: user.cpp: In function ‘int main()’: user.cpp:156:21: warning: unused variable ‘a’ [-Wunused-variable] int a = nr, b = mp[car]; ^ user.cpp:156:29: warning: unused variable ‘b’ [-Wunused-variable] int a = nr, b = mp[car]; ^ user.cpp:128:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("showroom.in" , "r" , stdin); ^ user.cpp:129:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("showroom.out" , "w" , stdout); ^ user.cpp:131:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d" , &n , &a , &r , &k); ^