题解 | #牛牛吃草#

int n;
cin >> n;
vector<int> w(n);
vector<int> a(n);
for (int i = 0; i < n; i++) {
    cin >> w[i];
}
for (int i = 0; i < n; i++) {
    cin >> a[i];
}
vector<int> dp(n, 0);
for (int i = 0; i < n; i++) {
    dp[i] = w[i];
}
int sum = 0;
for (int i = 1; i < n; i++) {
    for (int j = 0; j < i; j++) {
        if ((i - j) % a[j] == 0) {
            dp[i] = max(dp[j] + w[i], dp[i]);
        }
    }
    sum = (sum < dp[i]) ? dp[i] : sum;
}
cout << sum;
return 0;