Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:11:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) ^ user.cpp: In function ‘void dfs1(int)’: user.cpp:22:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:54:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(c[i].size()>sol) ^