Compilare: user.cpp: In function ‘void perm(int)’: user.cpp:16:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[1+(N>>1)].size();++i) ^ user.cpp:18:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[N>>1].size();++i) ^ user.cpp:24:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[N>>1].size();++i) ^ user.cpp:26:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[N>>1].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:36:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[n].size();++i) ^