Contest: Codeforces Round 967 (Div. 2) Problem: 2001C - Guess The Tree
Please read my post, and if you don't like it, before downvoting, please leave a comment explaining why you didn't like my post!
I haven't dealt with this type of problem before, so I don't know what's happening here. Please help me.
here is my code
void solve() {
int n; cin>>n;
vector <int> v[1001];
vector <pair <int,int>> ans;
for(int i=2; i<=n; i++) {
cout << "? " << 1 << ' ' << i << endl;
cout.flush();
int a; cin>>a;
if(a==1) ans.push_back({1, i});
else v[a].push_back(i);
}
for(int i=2; i<=n; i++) {
for(auto j: v[i]) {
cout << "? " << i << ' ' << j << endl;
cout.flush();
int a; cin>>a;
if(a==-1) exit(0);
if(a==i or a==j) ans.push_back({i, j});
else v[a].push_back(j);
}
}
cout << "! ";
for(auto [x,y]: ans) cout << x << ' ' << y << spc;
cout << newl;
cout.flush();
// long_line;
return;
}
and here is my submission
You may be asking more than the limit.
This is my only one post on this topic!!
He meant that you may be taking more input than is given, so the program waits for input when nothing is left to input
I mean, you're trying to solve this problem by asking the interactive machine too many times, so you're going to make mistakes.
"They said that if more than 15n queries are made, the remaining queries will return -1. So, I added a logic where the program will terminate if -1 is received as input, and a wrong answer verdict will be given. So, this shouldn't be happening!
When you receive -1, you are already wrong. Therefore, you need to keep the number of times strictly under 15n.
Idleness happens when the tester is waiting for your code to output something but nothing is happening. I recommend you to make you make your own test case and do a hard dry run on that. You can see my submissions on this question to see how I am so eligible to say so :|
Your solution is outputting less than n-1 edges, so the validator is wating for more edges to come but your program is waiting for an input from the validator (cin>>n)