Compilare: user.cpp: In function ‘void add(int*, long long unsigned int)’: user.cpp:13:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i <= A[0] || t || B; t /= 10, B /= 10, ++i) ^ user.cpp: In function ‘int main()’: user.cpp:27:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("next.in", "r", stdin); ^ user.cpp:28:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("next.out", "w", stdout); ^ user.cpp:29:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); ^ user.cpp:33:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &k); ^ /tmp/cc4lANSk.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.