非常简单的做法（萌新题解）

非常 简单 的做法

#include <bits/stdc++.h>
using namespace std;

#define LL long long
#define mod = 998244353

#define all(x) x.begin(), x.end()
#define SUM(x) accumulate(all(x), 0ll)

int n;

bool Rcmp(int a, int b) {
    return a > b;
}

void Solve() {
    cin >> n;

    vector<int> Node(n + 1);
    for (int i = 1; i <= n; i ++) 
        cin >> Node[i];

    int Left = 0, Right = n + 1;
    int sumL = 0, sumR = 0;
    int tot = SUM(Node), ans = tot;

    while (Left < Right) {
        if (sumL == sumR) 
            ans = tot, Left ++, sumL += Node[Left], tot -= Node[Left];

        else {
            if (sumL > sumR)
                Right --, sumR += Node[Right], tot -= Node[Right];

            else
                Left ++, sumL += Node[Left], tot -= Node[Left];
        }
    }

    cout << ans << '\n';
}

signed main() {
    ios::sync_with_stdio(0), cin.tie(0);
    Solve();
}