dptoys.cpp

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

#define int long long
const int N = 100005;

int a[N], f[N], s[N];

void solve() {
    memset(a, 0, sizeof(a));
    memset(s, 0, sizeof(s));
    memset(f, 0x8f, sizeof(f)); f[0] = 0;
    int n; cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        s[i] = a[i] + s[i - 1];
    }
    int ans = 0;
    for (int i = 1; i <= n + 3; i++) {
        for (int j = 1; j <= 3; j++) if (i >= j * 2) {
            f[i] = max(f[i], f[i - j * 2] + s[i - j] - s[i - j * 2]);
        }
        ans = max(ans, f[i]);
    }
    cout << ans << '\n';
}

signed main() {
    int t; cin >> t;
    while (t--) solve();
}