oj.uz

답안 #443656

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
443656 2021-07-11T07:43:04 Z fsociety00 캥거루 (CEOI16_kangaroo) C++14
100 / 100
 38 ms 15988 KB 
#include<bits/stdc++.h>
using namespace std;

#define ll long long int
#define LD long double

const int N = 100010;

int inf = 1e9;
int mod = 1e9 + 7;

inline void add(int &a, int b) {
  a += b;
  if (a >= mod) a -= mod;
}

inline void sub(int &a, int b) {
  a -= b;
  if (a < 0) a += mod;
}

inline int mul(int a, int b) {
  return (int) ((long long) a * b % mod);
}

inline int power(int a, long long b) {
  int res = 1;
  while (b > 0) {
    if (b & 1) {
      res = mul(res, a);
    }
    a = mul(a, a);
    b >>= 1;
  }
  return res;
}

inline int inv(int a) {
  a %= mod;
  if (a < 0) a += mod;
  int b = mod, u = 0, v = 1;
  while (a) {
    int t = b / a;
    b -= t * a; swap(a, b);
    u -= t * v; swap(u, v);
  }
  assert(b == 1);
  if (u < 0) u += mod;
  return u;
}


signed main()
{
//    freopen("kangaroo.in", "r", stdin);
//    freopen("kangaroo.out", "w", stdout);

    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int n;
    cin >> n;

    int cs, cf;
    cin >> cs >> cf;

    int dp[n + 1][n + 2];
    memset(dp, 0, sizeof(dp));

    dp[1][1] = 1;

    for (int i = 2; i <= n; i++) {
        for (int j = 1; j <= i; j++) {
            if (i == cs || i == cf) {
                add(dp[i][j], dp[i - 1][j - 1]);
                add(dp[i][j], dp[i - 1][j]);
                continue;
            }
            add(dp[i][j], mul(j, dp[i - 1][j + 1]));
            int ins = j;
            if (i > cs) sub(ins, 1);
            if (i > cf) sub(ins, 1);
            add(dp[i][j], mul(ins, dp[i - 1][j - 1]));
        }
    }

    cout << dp[n][1] << "\n";

    return 0;
}

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 0 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 0 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 460 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 460 KB Output is correct
15 Correct 1 ms 460 KB Output is correct
16 Correct 1 ms 460 KB Output is correct
17 Correct 1 ms 460 KB Output is correct
18 Correct 1 ms 332 KB Output is correct
19 Correct 1 ms 460 KB Output is correct
20 Correct 1 ms 460 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 0 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 460 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 460 KB Output is correct
15 Correct 1 ms 460 KB Output is correct
16 Correct 1 ms 460 KB Output is correct
17 Correct 1 ms 460 KB Output is correct
18 Correct 1 ms 332 KB Output is correct
19 Correct 1 ms 460 KB Output is correct
20 Correct 1 ms 460 KB Output is correct
21 Correct 4 ms 1996 KB Output is correct
22 Correct 5 ms 2124 KB Output is correct
23 Correct 6 ms 2540 KB Output is correct
24 Correct 36 ms 15948 KB Output is correct
25 Correct 35 ms 15948 KB Output is correct
26 Correct 36 ms 15988 KB Output is correct
27 Correct 38 ms 15820 KB Output is correct
28 Correct 21 ms 9036 KB Output is correct