Compilare: main.cpp: In function 'int dfs(int)': main.cpp:21:23: 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:61:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < v[i].size(); ++j) { ~~^~~~~~~~~~~~~ main.cpp:72:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < v[i].size(); ++j) { ~~^~~~~~~~~~~~~