Submission #503830

#	Time	Username	Problem	Language	Result	Execution time	Memory
503830		tabr	Linear Garden (IOI08_linear_garden)	C++17	95 / 100	1567 ms	2272 KiB

linear_garden

#include <bits/stdc++.h>
using namespace std;
#ifdef tabr
#include "library/debug.cpp"
#else
#define debug(...)
#endif

long long mod = 2;

struct mint {
    long long value;
    mint(long long x = 0) {
        value = x % mod;
        if (value < 0) value += mod;
    }
    mint& operator+=(const mint& other) {
        if ((value += other.value) >= mod) value -= mod;
        return *this;
    }
    mint& operator-=(const mint& other) {
        if ((value -= other.value) < 0) value += mod;
        return *this;
    }
    mint& operator*=(const mint& other) {
        value = value * other.value % mod;
        return *this;
    }
    mint& operator/=(const mint& other) {
        long long a = 0, b = 1, c = other.value, m = mod;
        while (c != 0) {
            long long t = m / c;
            m -= t * c;
            swap(c, m);
            a -= t * b;
            swap(a, b);
        }
        a %= mod;
        if (a < 0) a += mod;
        value = value * a % mod;
        return *this;
    }
    friend mint operator+(const mint& lhs, const mint& rhs) { return mint(lhs) += rhs; }
    friend mint operator-(const mint& lhs, const mint& rhs) { return mint(lhs) -= rhs; }
    friend mint operator*(const mint& lhs, const mint& rhs) { return mint(lhs) *= rhs; }
    friend mint operator/(const mint& lhs, const mint& rhs) { return mint(lhs) /= rhs; }
    mint& operator++() { return *this += 1; }
    mint& operator--() { return *this -= 1; }
    mint operator++(int) {
        mint result(*this);
        *this += 1;
        return result;
    }
    mint operator--(int) {
        mint result(*this);
        *this -= 1;
        return result;
    }
    mint operator-() const { return mint(-value); }
    bool operator==(const mint& rhs) const { return value == rhs.value; }
    bool operator!=(const mint& rhs) const { return value != rhs.value; }
    bool operator<(const mint& rhs) const { return value < rhs.value; }
};
string to_string(const mint& x) {
    return to_string(x.value);
}
ostream& operator<<(ostream& stream, const mint& x) {
    return stream << x.value;
}
istream& operator>>(istream& stream, mint& x) {
    stream >> x.value;
    x.value %= mod;
    if (x.value < 0) x.value += mod;
    return stream;
}

mint power(mint a, long long n) {
    mint res = 1;
    while (n > 0) {
        if (n & 1) {
            res *= a;
        }
        a *= a;
        n >>= 1;
    }
    return res;
}

vector<mint> fact(1, 1);
vector<mint> finv(1, 1);

mint C(int n, int k) {
    if (n < k || k < 0) {
        return mint(0);
    }
    while ((int) fact.size() < n + 1) {
        fact.emplace_back(fact.back() * (int) fact.size());
        finv.emplace_back(mint(1) / fact.back());
    }
    return fact[n] * finv[k] * finv[n - k];
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n >> mod;
    string s;
    cin >> s;
    vector<vector<vector<mint>>> dp(7, vector<vector<mint>>(7, vector<mint>(7)));
    int mn = 3;
    int mx = 3;
    int now = 3;
    for (int i = 0; i < n; i++) {
        vector<vector<vector<mint>>> new_dp(7, vector<vector<mint>>(7, vector<mint>(7)));
        for (int x = 1; x < 7; x++) {
            for (int y = x + 1; y < min(6, x + 3); y++) {
                for (int z = x; z <= y; z++) {
                    if (y - min(z - 1, x) < 3) {
                        new_dp[z - 1][min(z - 1, x)][y] += dp[z][x][y];
                    }
                    if (min(z + 1, y) - x < 3) {
                        new_dp[z + 1][x][max(z + 1, y)] += dp[z][x][y];
                    }
                }
            }
        }
        if (s[i] == 'P') {
            if (mx - min(mn, now - 1) < 3) {
                new_dp[now - 1][min(mn, now - 1)][mx]++;
            }
            now++;
            mx = max(mx, now);
        } else {
            now--;
            mn = min(mn, now);
        }
        swap(dp, new_dp);
    }
    mint ans = 1;
    for (int i = 0; i < 7; i++) {
        for (int j = i + 1; j < min(7, i + 3); j++) {
            for (int k = i; k <= j; k++) {
                ans += dp[k][i][j];
            }
        }
    }
    cout << ans << '\n';
    return 0;
}

• Subtask 1: 2 / 2
• Subtask 2: 2 / 2
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
• Subtask 6: 4 / 4
• Subtask 7: 4 / 4
• Subtask 8: 4 / 4
• Subtask 9: 4 / 4
• Subtask 10: 4 / 4
• Subtask 11: 4 / 4
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 5 / 5
• Subtask 15: 5 / 5
• Subtask 16: 5 / 5
• Subtask 17: 5 / 5
• Subtask 18: 5 / 5
• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5
• Subtask 22: 5 / 5
• Subtask 23: 0 / 5