Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:16:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[k].size();i++) ^ user.cpp: In function ‘void dfst(int)’: user.cpp:27:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<t[k].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:61:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<sol[i].size();j++) ^