oj.uz

답안 #894195

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
894195 2023-12-28T02:45:09 Z noiaint 캥거루 (CEOI16_kangaroo) C++17
100 / 100
 24 ms 14424 KB 
#include <bits/stdc++.h>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1 << (x))
#define file ""
using namespace std;

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
long long rand(long long l, long long r) {
    return l + rd() % (r - l + 1);
}

const int N = 2e3 + 5;
const int mod = 1e9 + 7; // 998244353;
const int inf = INT_MAX;
const long long llinf = LLONG_MAX;
const int lg = 25; // lg + 1

template<class X, class Y> bool minimize(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maximize(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
template<class X, class Y> bool add(X &a, Y b) {
    a += b;
    while (a >= mod) a -= mod;
    while (a < 0) a += mod;
    return true;
}

int n, s, e;
int f[N][N];

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    // freopen(file".inp", "r",stdin);
    // freopen(file".out", "w",stdout);

    cin >> n >> s >> e;

    f[0][0] = 1;

    for (int i = 0; i < n; ++i) for (int j = 0; j <= i; ++j) {
        if (i + 1 == s || i + 1 == e) {
            // one place we can put i

            // create new one in head/ tail
            add(f[i + 1][j + 1], f[i][j]);

            // append
            add(f[i + 1][j], f[i][j]);
        } else {
            // create new one
            add(f[i + 1][j + 1], 1LL * f[i][j] * (j + 1 - (i + 1 > s) - (i + 1 > e)) % mod);

            // we can't append

            // unite
            if (j > 0) add(f[i + 1][j - 1], 1LL * f[i][j] * (j - 1) % mod);
        }
    }

    cout << f[n][1];
    
    return 0;
}

/*
restriction
a[i] < a[j] > a[k]
*/

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 464 KB Output is correct
5 Correct 0 ms 464 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 0 ms 604 KB Output is correct
8 Correct 0 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 0 ms 604 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 464 KB Output is correct
5 Correct 0 ms 464 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 0 ms 604 KB Output is correct
8 Correct 0 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 0 ms 604 KB Output is correct
12 Correct 1 ms 1116 KB Output is correct
13 Correct 1 ms 1116 KB Output is correct
14 Correct 1 ms 1116 KB Output is correct
15 Correct 1 ms 1116 KB Output is correct
16 Correct 1 ms 1116 KB Output is correct
17 Correct 1 ms 1236 KB Output is correct
18 Correct 1 ms 1236 KB Output is correct
19 Correct 1 ms 1112 KB Output is correct
20 Correct 1 ms 1116 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 464 KB Output is correct
5 Correct 0 ms 464 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 0 ms 604 KB Output is correct
8 Correct 0 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 604 KB Output is correct
11 Correct 0 ms 604 KB Output is correct
12 Correct 1 ms 1116 KB Output is correct
13 Correct 1 ms 1116 KB Output is correct
14 Correct 1 ms 1116 KB Output is correct
15 Correct 1 ms 1116 KB Output is correct
16 Correct 1 ms 1116 KB Output is correct
17 Correct 1 ms 1236 KB Output is correct
18 Correct 1 ms 1236 KB Output is correct
19 Correct 1 ms 1112 KB Output is correct
20 Correct 1 ms 1116 KB Output is correct
21 Correct 5 ms 4184 KB Output is correct
22 Correct 4 ms 4084 KB Output is correct
23 Correct 4 ms 4444 KB Output is correct
24 Correct 24 ms 14172 KB Output is correct
25 Correct 22 ms 14424 KB Output is correct
26 Correct 24 ms 14172 KB Output is correct
27 Correct 22 ms 14172 KB Output is correct
28 Correct 14 ms 10164 KB Output is correct