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답안 #115965

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
115965 2019-06-10T05:01:20 Z IOrtroiii 캥거루 (CEOI16_kangaroo) C++14
100 / 100
 27 ms 14208 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 2020;
const int mod = 1000000007;

int f[N][N];

void add(int &x, int y) {
   x += y; if (x >= mod) x -= mod;
}

int mul(int x, int y) {
   return (long long) x * y % mod;
}

int main() {
   ios_base::sync_with_stdio(false); cin.tie(0);
   int n, cs, cf;
   cin >> n >> cs >> cf;
   f[1][1] = 1;
   for (int i = 2; i <= n; ++i) {
      for (int j = 1; j < i; ++j) {
         if (i == cs || i == cf) {
            add(f[i][j], f[i - 1][j]);
            add(f[i][j + 1], f[i - 1][j]);
         } else {
            if (j >= 2) add(f[i][j - 1], mul(f[i - 1][j], j - 1));
            int k = j - (i > cs) - (i > cf) + 1;
            add(f[i][j + 1], mul(f[i - 1][j], k));
         }
      }
   }
   cout << f[n][1] << '\n';
}

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 2 ms 512 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 2 ms 512 KB Output is correct
7 Correct 2 ms 512 KB Output is correct
8 Correct 2 ms 512 KB Output is correct
9 Correct 2 ms 512 KB Output is correct
10 Correct 2 ms 512 KB Output is correct
11 Correct 2 ms 512 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 2 ms 512 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 2 ms 512 KB Output is correct
7 Correct 2 ms 512 KB Output is correct
8 Correct 2 ms 512 KB Output is correct
9 Correct 2 ms 512 KB Output is correct
10 Correct 2 ms 512 KB Output is correct
11 Correct 2 ms 512 KB Output is correct
12 Correct 3 ms 1152 KB Output is correct
13 Correct 3 ms 1152 KB Output is correct
14 Correct 3 ms 1280 KB Output is correct
15 Correct 3 ms 1280 KB Output is correct
16 Correct 3 ms 1152 KB Output is correct
17 Correct 16 ms 1280 KB Output is correct
18 Correct 3 ms 1152 KB Output is correct
19 Correct 3 ms 1280 KB Output is correct
20 Correct 3 ms 1280 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 2 ms 512 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 2 ms 512 KB Output is correct
7 Correct 2 ms 512 KB Output is correct
8 Correct 2 ms 512 KB Output is correct
9 Correct 2 ms 512 KB Output is correct
10 Correct 2 ms 512 KB Output is correct
11 Correct 2 ms 512 KB Output is correct
12 Correct 3 ms 1152 KB Output is correct
13 Correct 3 ms 1152 KB Output is correct
14 Correct 3 ms 1280 KB Output is correct
15 Correct 3 ms 1280 KB Output is correct
16 Correct 3 ms 1152 KB Output is correct
17 Correct 16 ms 1280 KB Output is correct
18 Correct 3 ms 1152 KB Output is correct
19 Correct 3 ms 1280 KB Output is correct
20 Correct 3 ms 1280 KB Output is correct
21 Correct 7 ms 3840 KB Output is correct
22 Correct 7 ms 4096 KB Output is correct
23 Correct 7 ms 4480 KB Output is correct
24 Correct 25 ms 14200 KB Output is correct
25 Correct 27 ms 14200 KB Output is correct
26 Correct 27 ms 14172 KB Output is correct
27 Correct 27 ms 14208 KB Output is correct
28 Correct 19 ms 10240 KB Output is correct