Compilare: user.cpp: In function ‘int f(int)’: user.cpp:20:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (poz + poz > strlen(s)) { ^ user.cpp:26:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i; j < strlen(s) - 1 - poz; j++) { ^ user.cpp: In function ‘int main()’: user.cpp:41:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("palind.in", "r", stdin); ^ user.cpp:42:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("palind.out", "w", stdout); ^ user.cpp:50:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ user.cpp:52:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/cc7cnhNS.o: In function `main': user.cpp:(.text.startup+0x74): warning: the `gets' function is dangerous and should not be used.