abc 374

A

signed main()
{
    IOS;
    string a;
    cin >> a;
    int n = a.size();
    if (a[n - 3] == 's' && a[n - 2] == 'a' && a[n - 1] == 'n')
    {
        cout << "Yes" << endl;
    }
    else
    {
        cout << "No" << endl;
    }
    return 0;
}

B

signed main() {
    IOS;
    string a;
    string b;
    cin >> a >> b;
    if (a == b) {
        cout << 0 << endl;
        return 0;
    }
    for (int i = 0; i < a.size() && i < b.size(); i++) {
        if (a[i] != b[i]) {
            cout << i + 1 << endl;
            return 0;
        }
    }
    cout << min(a.size(), b.size()) + 1 << endl;

    return 0;
}

C

signed main() {
    IOS;
    int n;
    cin >> n;
    vector<int> a(n);
    int ans = 0;
    for (int &v : a) {
        cin >> v;
        ans += v;
    }
    int res = 1e18;
    for (int i = 0; i < (1 << n); i++)
    {
        ll sum = 0;
        for (int j = 0; j < n; j++) {
            if ((i >> j) & 1) {
                sum += a[j];
            }
        }
        res = min(res, (int)max(ans - sum, sum));
    }
    cout << res << endl;
    return 0;
}

D

#define MAX 10
double dp[MAX][2];
int n;
double S, T;
double sx[100], sy[100], tx[100], ty[100];
double dis(double x, double y, double xx, double yy)
{
    return sqrt((x - xx) * (x - xx) + (y - yy) * (y - yy));
}
signed main()
{
    IOS;
    cin >> n >> S >> T;
    for (int i = 1; i <= n; i++)
    {
        cin >> sx[i] >> sy[i] >> tx[i] >> ty[i];
    }
    double ans = 1111111111.0;
    vector<int> v(n);
    for (int i = 0; i < n; i++)
    {
        v[i] = i + 1;
    }
    do
    {
        double dp[15][2] = {0.0};
        for (int op = 0; op < n; op++)
        {
            int i = v[op];
            int j = op ? v[op - 1] : 0;
            double len = dis(sx[i], sy[i], tx[i], ty[i]) / T;
            dp[i][0] = min(dp[j][0] + dis(sx[j], sy[j], tx[i], ty[i]) / S, dp[j][1] + dis(tx[j], ty[j], tx[i], ty[i]) / S) + len;
            dp[i][1] = min(dp[j][0] + dis(sx[j], sy[j], sx[i], sy[i]) / S, dp[j][1] + dis(tx[j], ty[j], sx[i], sy[i]) / S) + len;
            //cout << len << ' ' << dp[i][0] << ' ' << dp[i][1] << ' ' << i << ' ' << j << endl;
        }
        ans = min(ans, (double)min(dp[v[n - 1]][0], dp[v[n - 1]][1]));
        //out << ans << endl;
    } while (next_permutation(v.begin(), v.end()));
    cout << fixed << setprecision(20) << ans << endl;
    return 0;
}

E

signed main() {
    IOS;
    int n, x;
    cin >> n >> x;

    vector<ll> a(n), p(n), b(n), q(n);
    for (int i = 0; i < n; i++)
    {
        cin >> a[i] >> p[i] >> b[i] >> q[i];
        if (p[i] * b[i] > q[i] * a[i])
        {
            swap(a[i], b[i]);
            swap(p[i], q[i]);
        }
    }

    auto check = [&](int mid)
    {
        ll X = x;
        for (int i = 0; i < n; i++)
        {
            ll ans = 1E18;
            for (int j = 0; j <= 100; j++)
            {
                ll s = j * q[i];
                ll r = mid - j * b[i];
                if (r > 0)
                    s += (r + a[i] - 1) / a[i] * p[i];

                ans = min(ans, s);
            }

            X -= ans;
            if (X < 0)
                return false;
        }

        return true;
    };

    int l = -1, r = 1E9 + 7;
    while (l + 1 < r) {
        int mid = (l + r) / 2;
        if (check(mid))
            l = mid;
        else
            r = mid;
    }
    cout << r - 1<< endl;

    return 0;
}

F

signed main() {
    IOS;
    int n, k, x;
    cin >> n >> k >> x;
    vector<ll> t(n);
    for (ll &a : t)
        cin >> a;
    vector<ll> clk;
    for(ll &a : t) {
        for (int i = 0; i <= n; i++) {
            clk.push_back(a + i * x);
        }
    }
    sort(clk.begin(), clk.end());
    clk.erase(unique(clk.begin(), clk.end()), clk.end());
    ll len = clk.size();
    vector<vector<ll> > dp(len + 1, vector<ll>(n + 1, 1e18));
    dp[0][0] = 0;
    ll res = 1e18;
    ll nxt = 0;
    for (int i = 0; i < len; i++) {
        while (nxt < len && clk[nxt] < clk[i] + x) {
            nxt++;
        }
        for (int j = 0; j < n; j++) {
            if (dp[i][j] > 1e17) {
                continue;
            }
            dp[i + 1][j] = min(dp[i + 1][j], dp[i][j]);
            ll mv = dp[i][j];
            for (ll m = j; m < min(j + k, n); m++) {
                if (clk[i] < t[m]) {
                    break;
                }
                mv += (clk[i] - t[m]);
                if (m == n - 1) {
                    res = min(res, mv);
                } else {
                    dp[nxt][m + 1] = min(dp[nxt][m + 1], mv);
                }
            }
        }
    }
    cout << res << '\n';
    return 0;
}