Submission #345571

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Source Code Expand

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <set>

using namespace std;
int main(){
    int N;
    cin >> N;
    int max_i = 1;
    int max_dist = -1;
    for(int i = 2; i <= N; i++){
        int dist;
        cout << "? " << 1 << " " << i << endl;
        cin >> dist;
        if(dist > max_dist){
            max_i = i;
            max_dist = dist;
        }
    }
    for(int i = 1; i <= N; i++){
        if(i == max_i) continue;
        int dist;
        cout << "? " << max_i << " " << i << endl;
        cin >> dist;
        max_dist = max(max_dist, dist);
    }
    cout << "! " << max_dist << endl;
    return 0;
}

Submission Info

Judge Result