Compilare: main.cpp: In function 'int sol(int)': main.cpp:53:13: warning: unused variable 'ret' [-Wunused-variable] int ret(0) ; ^~~ main.cpp:54:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ main.cpp: In function 'int main()': main.cpp:76:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cifra4.in", "r", stdin) ; ^ main.cpp:77:44: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cifra4.out", "w", stdout) ; ^