Compilare: user.cpp: In function ‘int main()’: user.cpp:55:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("sortnet.in", "r", stdin); ^ user.cpp:56:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("sortnet.out", "w", stdout); ^ user.cpp:58:29: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (sir, 1, 40000, stdin); ^ user.cpp:20:20: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] return ((X & (1<<pos)) > 0); ^ user.cpp:72:9: note: ‘pos’ was declared here int pos, val = gray (i) ^ gray (i - 1); ^