Compilare: user.cpp: In function ‘int main()’: user.cpp:13:25: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char (*)[1000001]’ [-Wformat=] scanf ("%s\n",&s); ^ user.cpp:8:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("prefix.in","r",stdin); ^ user.cpp:9:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("prefix.out","w",stdout); ^ user.cpp:11:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d/n",&t); ^ user.cpp:13:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s\n",&s); ^