题解 | 宵暗的妖怪

#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
using ld = long double;
using PII=pair<ll,ll>;
using PIII=pair<int,pair<int,int>>;
const ld ESP = 1e-10;
const ld PI = acosl(-1);
const int N=1e5+10;
const int M=2e5+10;
// const int mod = 1000000007;
const int mod = 998244353;
//随机化
random_device rd;
mt19937 gen(rd());
uniform_int_distribution<> dis(1, 1000000000);
// cout<<fixed<<setprecision(10);


void solve(){
    int n;
    cin>>n;
    vector<ll> dp(n+1,0);
    dp[0]=dp[1]=dp[2]=0;
    ll a[n+1];
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    for(int i=3;i<=n;i++){
        dp[i]=max(dp[i-3]+a[i-1],dp[i]);
        dp[i]=max(dp[i-1],dp[i]);
    }
    cout<<dp[n];
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int _=1;
    // cin>>_;
    while(_--){
        solve();
    }
    return 0;
}