Compilare: user.cpp: In function ‘int main()’: user.cpp:31:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (s.size() != 2 * n) { ~~~~~~~~~^~~~~~~~ user.cpp:14:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("puteri35.in", "r", stdin); ^ user.cpp:15:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("puteri35.out", "w", stdout); ^ user.cpp:19:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^