Submission #991861

#	Time	Username	Problem	Language	Result	Execution time	Memory
991861		danikoynov	Security Gate (JOI18_security_gate)	C++14	12 / 100	5039 ms	460 KiB

securitygate

#include<bits/stdc++.h>
#define endl '\n'

using namespace std;
typedef long long ll;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

const ll mod = 1000000007;

int n;
string s;

void solve()
{
    cin >> n >> s;
    s = "#" + s;
    int cnt = 0;
    for (int i = 1; i <= n; i ++)
    {
        if (s[i] == 'x')
            cnt ++;
    }

    int res = 0;
    for (int mask = 0; mask < (1 << cnt); mask ++)
    {
        int bit = 0;
        string t = s;
        for (int i = 1; i <= n; i ++)
        {
            if (t[i] == 'x')
            {
                //cout << "here " << mask << " " << bit << " " << (mask & (1 << bit)) << endl;
                if ((mask & (1 << bit)) > 0)
                    t[i] = '(';
                else
                    t[i] = ')';
                bit ++;
            }
        }


        bool done = false;
        for (int i = 1; i <= n; i ++)
            for (int j = i; j <= n; j ++)
            {
                int pf = 0;

                bool tf = true;
                for (int d = 1; d <= n; d ++)
                {
                    int c = -1;
                    if (t[d] == '(')
                        c = 1;
                    if (d >= i && d <= j)
                        c *= -1;
                    pf += c;
                    if (pf < 0)
                    {
                        tf = false;
                        break;
                    }
                }
                if (pf != 0)
                    tf = false;
                if (tf)
                {
                    ///cout << i << " : " << j << endl;
                    done = true;
                    break;
                }
            }
        int pf = 0;

        bool tf = true;
        for (int d = 1; d <= n; d ++)
        {
            int c = -1;
            if (t[d] == '(')
                c = 1;
            pf += c;
            if (pf < 0)
            {
                tf = false;
                break;
            }
        }
        if (pf != 0)
            tf = false;
        if (tf)
        {
            ///cout << i << " : " << j << endl;
            done = true;
        }
        if (done)
            res ++;

        ///cout << t << " " << done << endl;
    }
    cout << res << endl;
}

int main()
{
    speed();
    solve();
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 0 / 18
• Subtask 4: 0 / 43
• Subtask 5: 0 / 27