1975C-ChamoAndMochasArray.cpp

#include <cstdio>
#include <vector>
#include <set>
#include <iterator>
#include <algorithm>

int main(){

    long t; scanf("%ld", &t);
    while(t--){
        long n; scanf("%ld", &n);
        std::vector<long> v(n); for(long p = 0; p < n; p++){scanf("%ld", &v[p]);}
        if(n == 2){printf("%ld\n", v[0] < v[1] ? v[0] : v[1]); continue;}

        std::multiset<long> s;
        s.insert(v[0]); s.insert(v[1]); s.insert(v[2]);
        long res(*std::next(s.begin() , 1));
        for(long p = 3; p < n; p++){
            s.erase(s.find(v[p - 3]));
            s.insert(v[p]);
            long cand = *(std::next(s.begin(), 1));
            res = (res > cand ? res : cand);
        }

        printf("%ld\n", res);
    }

}