Compilare: user.cpp: In function ‘int main()’: user.cpp:36:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<V[i].size(); j++) ~^~~~~~~~~~~~ user.cpp:23:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("radixsort.in", "r", stdin); ^ user.cpp:24:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("radixsort.out", "w", stdout); ^