Compilare: user.cpp: In function ‘int main()’: user.cpp:51:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<words.size(); ++i) ^ user.cpp:53:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] printf("%s%s", words[i].c_str(), i+1 == words.size() ? "":" "); ^ user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("litere2.in", "r", stdin); ^ user.cpp:16:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("litere2.out", "w", stdout); ^ user.cpp:21:23: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(buf, sz, stdin); ^