Compilare: user.cpp: In function ‘int main()’: user.cpp:10:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<x.size();i++){ ~^~~~~~~~~ user.cpp:12:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i+k-1< x.size()) ~~~~~^~~~~~~~~~ user.cpp:7:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("blis.in", "r", stdin); ^ user.cpp:8:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("blis.out", "w", stdout); ^