Compilare: user.cpp: In function ‘void SUBST1::solve(int)’: user.cpp:64:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", str); ^ user.cpp: In function ‘int main()’: user.cpp:84:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prefix2.in", "r", stdin); ^ user.cpp:85:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prefix2.out", "w", stdout); ^