Compilare: user.cpp: In function ‘int main()’: user.cpp:35:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j <= len; ++j) { ^ user.cpp:14:15: warning: unused variable ‘aux’ [-Wunused-variable] int t, n, k, aux, ans; ^ user.cpp:11:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parola.in", "r", stdin); ^ user.cpp:12:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parola.out", "w", stdout); ^ user.cpp:19:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp:25:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:27:10: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ user.cpp:28:10: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccNZZC3z.o: In function `main': user.cpp:(.text.startup+0x9a): warning: the `gets' function is dangerous and should not be used.