Main.cc:12:28: error: declaration of ‘c’ as array of references long long dfs(long long &c[]){ ^ Main.cc: In function ‘long long int dfs(...)’: Main.cc:25:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ Main.cc: In function ‘int main()’: Main.cc:27:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&n); ~~~~~^~~~~~~~~~~ Main.cc:29:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&a[i]); ~~~~~^~~~~~~~~~~~~~ Main.cc:32:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&c[i]); ~~~~~^~~~~~~~~~~~~~