oj.uz

답안 #1095844

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1095844 2024-10-03T10:08:15 Z windowwife Žarulje (COI15_zarulje) C++14
100 / 100
 326 ms 24732 KB 
#include<bits/stdc++.h>
#define ll long long
#define task ""
using namespace std;
const int maxn = 1e6 + 2, LG = 20, mod = 1e9 + 7;
int n, q, f[maxn], invf[maxn], a[maxn], x, t[maxn], res = 1, ans[maxn];
unordered_map<int, int> L, R;
vector<int> stL, stR;
vector<pair<int, int>> changes;
int power (int a, int b)
{
    int res = 1;
    for (; b > 0; b >>= 1)
    {
        if (b & 1) res = 1LL * res * a % mod;
        a = 1LL * a * a % mod;
    }
    return res;
}
void prep ()
{
    f[0] = 1;
    for (int i = 1; i < maxn; i++) f[i] = 1LL * f[i - 1] * i % mod;
    invf[maxn - 1] = power(f[maxn - 1], mod - 2);
    for (int i = maxn - 2; i >= 0; i--) invf[i] = 1LL * invf[i + 1] * (i + 1) % mod;
}
int C (int k, int n)
{
    return 1LL * f[n] * invf[k] % mod * invf[n - k] % mod;
}
int main()
{
    //freopen(task".INP", "r", stdin);
    //freopen(task".OUT", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    prep();
    cin >> n >> q;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = n; i >= 1; i--)
    {
        while (!stR.empty() && stR.back() > a[i])
        {
            changes.push_back({0, stR.back()});
            res = 1LL * res * power(C(R[stR.back()], L[stR.back()] + R[stR.back()]), mod - 2) % mod;
            R[stR.back()]--;
            res = 1LL * res * C(R[stR.back()], L[stR.back()] + R[stR.back()]) % mod;
            stR.pop_back();
        }
        stR.push_back(a[i]);
        changes.push_back({1, a[i]});
        res = 1LL * res * power(C(R[a[i]], L[a[i]] + R[a[i]]), mod - 2) % mod;
        R[a[i]]++;
        res = 1LL * res * C(R[a[i]], L[a[i]] + R[a[i]]) % mod;
        t[i] = changes.size();
    }
    for (int i = 1; i <= n; i++)
    {
        while ((int)changes.size() > t[i + 1])
        {
            if (changes.back().first == 0)
            {
                stR.push_back(changes.back().second);
                res = 1LL * res * power(C(R[stR.back()], L[stR.back()] + R[stR.back()]), mod - 2) % mod;
                R[stR.back()]++;
                res = 1LL * res * C(R[stR.back()], L[stR.back()] + R[stR.back()]) % mod;
            }
            else
            {
                res = 1LL * res * power(C(R[stR.back()], L[stR.back()] + R[stR.back()]), mod - 2) % mod;
                R[stR.back()]--;
                res = 1LL * res * C(R[stR.back()], L[stR.back()] + R[stR.back()]) % mod;
                stR.pop_back();
            }
            changes.pop_back();
        }
        if (i > 1)
        {
            while (!stL.empty() && stL.back() > a[i - 1])
            {
                res = 1LL * res * power(C(L[stL.back()], L[stL.back()] + R[stL.back()]), mod - 2) % mod;
                L[stL.back()]--;
                res = 1LL * res * C(L[stL.back()], L[stL.back()] + R[stL.back()]) % mod;
                stL.pop_back();
            }
            stL.push_back(a[i - 1]);
            res = 1LL * res * power(C(L[a[i - 1]], L[a[i - 1]] + R[a[i - 1]]), mod - 2) % mod;
            L[a[i - 1]]++;
            res = 1LL * res * C(L[a[i - 1]], L[a[i - 1]] + R[a[i - 1]]) % mod;
        }
        ans[i] = res;
    }
    while (q--)
    {
        cin >> x;
        cout << ans[x] << '\n';
    }
}

Subtask #1
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 8284 KB Output is correct
2 Correct 14 ms 8284 KB Output is correct
3 Correct 17 ms 8348 KB Output is correct
4 Correct 15 ms 8280 KB Output is correct
5 Correct 16 ms 8284 KB Output is correct
6 Correct 16 ms 8284 KB Output is correct

Subtask #2
38.0 / 38.0

# 결과 실행 시간 메모리 Grader output
1 Correct 145 ms 11080 KB Output is correct
2 Correct 252 ms 13812 KB Output is correct
3 Correct 258 ms 13764 KB Output is correct
4 Correct 276 ms 13876 KB Output is correct
5 Correct 275 ms 14520 KB Output is correct
6 Correct 305 ms 21660 KB Output is correct
7 Correct 313 ms 24428 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 8284 KB Output is correct
2 Correct 14 ms 8284 KB Output is correct
3 Correct 17 ms 8348 KB Output is correct
4 Correct 15 ms 8280 KB Output is correct
5 Correct 16 ms 8284 KB Output is correct
6 Correct 16 ms 8284 KB Output is correct
7 Correct 145 ms 11080 KB Output is correct
8 Correct 252 ms 13812 KB Output is correct
9 Correct 258 ms 13764 KB Output is correct
10 Correct 276 ms 13876 KB Output is correct
11 Correct 275 ms 14520 KB Output is correct
12 Correct 305 ms 21660 KB Output is correct
13 Correct 313 ms 24428 KB Output is correct
14 Correct 25 ms 8668 KB Output is correct
15 Correct 147 ms 11968 KB Output is correct
16 Correct 265 ms 15944 KB Output is correct
17 Correct 271 ms 14780 KB Output is correct
18 Correct 280 ms 15800 KB Output is correct
19 Correct 282 ms 14936 KB Output is correct
20 Correct 309 ms 22172 KB Output is correct
21 Correct 326 ms 24732 KB Output is correct