Compilare: main.cpp: In function 'void dfs1(int, int)': main.cpp:22:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < arb1[node].size(); i++) ~~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void dfs2(int, int)': main.cpp:43:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < arb2[node].size(); i++) ~~^~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void check_cycle(int, int)': main.cpp:71:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < red[node].size(); i++) ~~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:147:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < ans.size(); i++) ~~^~~~~~~~~~~~