Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:20:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v[nod].size(); ++i) ~^~~~~~~~~~~~~~ main.cpp: In function 'void write()': main.cpp:47:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<solution.size(); ++i) ~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:59:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<a[i].size(); ++j) ~^~~~~~~~~~~~