Card game

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

const int N = 1e6 + 5;
const int MOD = 1e9 + 7;

int n;
int x[N];
int dp[N];

signed main() {
    cin.tie(0)->sync_with_stdio(0);

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

    memset(dp, -1, sizeof dp);
    dp[0] = 0;
    for (int i = 3; i <= n; i++) {
        // take
        dp[i] = max(dp[i], dp[i - 3] + x[i - 1]);
        // don't take
        dp[i] = max(dp[i], dp[i - 1]);
    }
    cout << dp[n] << '\n';
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: ACCEPTED

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED