题解 | 不相邻取数

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

int main() {
    int n;
    cin >> n;
    long long take_prev_prev = 0, take_prev = 0; // dp[i-2], dp[i-1]

    for (int i = 0; i < n; ++i) {
        long long x;
        cin >> x;
        long long cur = max(take_prev, take_prev_prev + x); // 取或不取当前
        take_prev_prev = take_prev;
        take_prev = cur;
    }
    cout << take_prev << '\n';
    return 0;
}