Compilare: user.cpp: In function ‘int main()’: user.cpp:56:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("decod.in", "r", stdin); ^ user.cpp:57:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("decod.out", "w", stdout); ^ user.cpp:59:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &K, &p, &cod); ^ user.cpp:66:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ /tmp/cci9zz6F.o: In function `main': user.cpp:(.text.startup+0xc6): warning: the `gets' function is dangerous and should not be used.