Compilare: main.cpp: In function 'bool check(ll)': main.cpp:30:12: warning: unused variable 'cnt' [-Wunused-variable] ll cnt = 0; ^~~ main.cpp: In function 'int main()': main.cpp:43:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fact.in", "r", stdin); ^ main.cpp:44:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("fact.out", "r", stdin); ^ main.cpp:61:20: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized] cout << ans; ^