Submission #3042921

---

Source Code Expand

#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;
ll n, d, a[15], b[25], res;
vector<ll> memo;
const ll INF = 1000000000;

void dfs(ll x){
    if (x == memo.size()){
        vector<ll> vec;
        ll sma = INF;
        for (ll i = 0; i <= 24; i++){
            if (b[i] == 0) continue;
            vec.push_back(i);
        }
        for (ll i = 1; i < vec.size(); i++){
            sma = min(sma, vec[i] - vec[i - 1]);
        }
        res = max(res, sma);
    } else {
        b[memo[x]] = 1;
        dfs(x + 1);
        b[memo[x]] = 0;
        b[24 - memo[x]] = 1;
        dfs(x + 1);
        b[24 - memo[x]] = 0;
    }
}

int main(void){
    // Your code here!
    cin >> n;
    for (ll i = 0; i < n; i++){
        cin >> d;
        a[d]++;
    }
    if (a[0] || a[12] > 1){
        cout << 0 << endl;
        return 0;
    }
    b[0] = 1, b[24] = 1;
    if (a[12] == 1) b[12] = 1;
    for (ll i = 1; i < 12; i++){
        if (a[i] > 2){
            cout << 0 << endl;
            return 0;
        } if (a[i] == 2){
            b[i] = 1;
            b[24 - i] = 1;
        } if (a[i] == 1){
            memo.push_back(i);
        }
    }
    dfs(0);
    cout << res << endl;
}

Submission Info

Judge Result