原题链接https://www.luogu.com.cn/problem/P8681

了解完全二叉树的性质

注意可能最后一层没有满

#include <iostream>
#include <string>
#include <cstring>
#include <algorithm>
#include <set>
#include <map>
#include <tuple>
#include <vector>
#define ll long long

const ll N = 1e5 + 10;
//ll n,m;
//ll op[N];

void solve(){
    ll n;
    std::cin >> n;
    std::vector<ll> op(n + 1);
    for(ll i = 1; i <= n; i ++){
        std::cin >> op[i];
        op[i] += op[i - 1];
    }
    ll kk = 1;
    ll res = 0;
    ll mxx = -1;
    ll ans = -1;
    ll uu = 0;
    while(res < n){
        uu ++;
//      std::cout << op[res + kk] - op[res] << "\n";
        if(mxx < op[std::min(res + kk,n)] - op[res]){
            ans = uu;
        }
        mxx = std::max(mxx,op[std::min(res + kk,n)] - op[res]);
        res += kk;
        kk *= 2;
    }
    std::cout << ans << "\n";
    return ;
}

int main(){
    ll t = 1;
    while(t --)
    solve();
    return 0;
}