Compilare: main.cpp: In function 'void solve_first(long long int, long long int)': main.cpp:25:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (long long i=0; i<edge[node].size(); i++){ ~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'void DFS(long long int)': main.cpp:34:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (long long i=0; i<edge[node].size(); i++){ ~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:91:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<ans.size(); i++) ~^~~~~~~~~~~