Submission #345650

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Source Code Expand

#include <iostream>

int N;

// uから一番遠い頂点を探す
int f(int u){
    int mx, mx_v;
    for(int v=1;v<=N;v++){
        if(v == u){continue;}
        std::cout << "? " << u << " " << v << std::endl;
        int d;
        std::cin >> d;

        if(d > mx){
            mx = d;
            mx_v = v;
        }
    }

    return mx_v;
}

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

    int u = f(1), v = f(u);
    std::cout << "? " << u << " " << v << std::endl;
    int d;
    std::cin >> d;

    std::cout << d << std::endl;
}

Submission Info

Judge Result