Compilare: main.cpp: In function 'void solve_first(long long int, long long int)': main.cpp:27:26: 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, long long int)': main.cpp:36:26: 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:83:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<ans.size(); i++) ~^~~~~~~~~~~ main.cpp:60:21: warning: unused variable 'j' [-Wunused-variable] long long V, i, j, src, dest; ^