Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:23:14: warning: the address of 'sol' will always evaluate as 'true' [-Waddress] viz[k] = sol; ^~~ main.cpp:28:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[k].size(); ++i) { ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:71:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < sol[i].size(); ++j) { ~~^~~~~~~~~~~~~~~