Compilare: user.cpp: In function ‘void insert(int)’: user.cpp:24:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (sz == A.size()) ^ user.cpp: In function ‘int main()’: user.cpp:102:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeap.in", "r", stdin); ^ user.cpp:103:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeap.out", "w", stdout); ^ /tmp/ccFggXrR.o: In function `main': user.cpp:(.text.startup+0x58): warning: the `gets' function is dangerous and should not be used.