Submission #661348

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Source Code Expand

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
	int N;
	cin >> N;

	vector<int> dist(N + 1);
	for(int i = 2 ; i <= N ; ++i) {
		cout << "? 1 " << i << endl;
		cout.flush();
		cin >> dist[i];
	}
	int vertex = max_element(dist.begin(), dist.end()) - dist.begin();
	vector<int>(N + 1).swap(dist);
	for(int i = 1 ; i <= N ; ++i) {
		if(i == vertex)
			continue;
		cout << "? " << vertex << " " << i << endl;
		cout.flush();
		cin >> dist[i];
	}
	cout << "! " << *max_element(dist.begin(), dist.end()) << endl;
	cout.flush();
}

Submission Info

Judge Result