Card game

#include <algorithm>
#include <cstdio>
#include <iostream>
#include <vector>

using namespace std;

int get_max(int end, vector<int> cards)
{
    if (end < 2) return 0;
    int res = max(get_max(end - 3, cards) + cards[end - 1], get_max(end - 1, cards));
    return res;
}

int main(int argc, char *argv[])
{
	// Read the input parameters
	int n;
	cin >> n;

	// Read values from one line
	vector<int> cards(n, 0);
	for (int i = 0; i < n - 1; i++) {
		cin >> cards[i];
	}
	/*for (int i = 0; i < n; i++) {*/
	/*	cout << cards[i];*/
	/*}*/
	/*   cout << "\n";*/

	vector<int> sums(n, 0);
    sums[2] = cards[1];
	for (int i = 3; i < n; i++) {
        /*cout << i << "\n";*/
        int previous = cards[i - 1];
        int a = 0;
        int index = i - 3;
        if (index >= 0) a = sums[index];
        /*int a = i - 3 >= 2 ? sums[i - 3] : 0;*/
        int b = sums[i - 1];
        /*cout << a << " " << b << "\n";*/
        /*sums[i] = max(a + current, b);*/
        /*cout << "i: "<< i << " cards[i - 1]: " << cards[i - 1] << " three before: " << a << " previous sum: " << b << "\n";*/
        /*cout << max(a + previous, b) << "\n";*/
        sums[i] = max(max(a + previous, b), cards[i - 1]);
    }
    /*cout << "\n";*/
    /*sums[n - 1] = sums[n - 2];*/

    /*for (int i = 0; i < n; i++) {*/
    /*    cout << sums[i] << "\n";*/
    /*}*/
    /*cout << "\n";*/

    cout << sums[n - 1] << "\n";
    /*cout << get_max(n - 1, cards) << "\n";*/
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED