Compilare: main.cpp: In function 'int main()': main.cpp:19:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("shop.in","r",stdin); ^ main.cpp:20:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("shop.out","w",stdout); ^ main.cpp:23:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %lld",&n,&c,&l); ^ main.cpp:26:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&C[i].val,&C[i].ct); ^