Compilare: user.cpp: In function ‘int main()’: user.cpp:11:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("staropramen.in","rt",stdin); ^ user.cpp:12:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("staropramen.out","wt",stdout); ^ user.cpp:14:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d\n",&t);t;--t) ^ user.cpp:16:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:18:59: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;++i) scanf("%c%c",&x,&s[i]),s[i]+=x-2*'0'; ^