Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:12:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<x[k].size();i++) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:18:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<xt[k].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:41:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sol[j].size();++i) ^