Dice Combinations

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

#define all(x)  begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sz(x)   (int)(x).size()                                 // signed size: avoids the unsigned .size() wrap bug

using ll  = long long;
using pii = pair<int,int>;
using vi  = vector<int>;

#ifdef LOCAL                                                    // compile with -DLOCAL to enable, silent on the judge
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "] = ", dbg_out(__VA_ARGS__)
template<class T> void dbg_out(T x) { cerr << x << '\n'; }
template<class T, class... R> void dbg_out(T x, R... r) { cerr << x << ", "; dbg_out(r...); }
#else
#define dbg(...)
#endif

int main() {
    cin.tie(0)->sync_with_stdio(0);    
    int n; cin >> n; 
    // int n,m; cin >> n >> m; 

    int a[7];
    for (int i = 0; i < 7; i++)
    {
        a[i] = 0;
    }
    a[6] = 1;
    ll val = 0;
    ll cst = pow(10,9) + 7;
    for (int i = 0; i < n; i++)
    {

        val += a[(i-1+7)%7];
        if(i>=6){
            val -= a[i%7];
        }
        a[i % 7] = val;
        val = val % cst;
        dbg(val, *a);
    }
    
    

    cout << val;

    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: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER