Compilare: user.cpp: In function ‘void fft(std::complex<double>*, int, int)’: user.cpp:25:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j = 0; ^ user.cpp: In function ‘int main()’: user.cpp:97:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bacterii2.in", "r", stdin); ^ user.cpp:98:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bacterii2.out", "w", stdout); ^ user.cpp: In function ‘char getch()’: user.cpp:78:36: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, size, 1, stdin); ^