Compilare: user.cpp: In function ‘int main()’: user.cpp:154:27: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char (*)[400005]’ [-Wformat=] scanf ("%s\n", &s); ^ user.cpp:147:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("frequent.in", "r", stdin); ^ user.cpp:148:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("frequent.out", "w", stdout); ^ user.cpp:152:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &k); ^ user.cpp:154:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s\n", &s); ^