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답안 #78741

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
78741 2018-10-08T08:48:04 Z triplem5ds 캥거루 (CEOI16_kangaroo) C++14
100 / 100
 82 ms 14472 KB 
/*
    dp[node][state];
    state 0 : the node before me is a server
    state 1 : the node before me isn't a server but it's covered by a server
    state 2 : the node before me is a server but it's not covered by a server
*/
#include <bits/stdc++.h>

using namespace std;

using ii = pair<int,int>;
using ll = long long;

const int mod = 1e9 + 7;
const int N = 2005;

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

int n, cs, cf;
int dp[N][N];
int main(){
#ifdef ONLINE_JUDGE
    ios_base::sync_with_stdio(0);
    cin.tie(0);
#endif // ONLINE_JUDGE

    cin >> n >> cs >> cf;

    dp[0][0] = 1;

    for(int i = 1; i < n; i++){

        if(i == cs ||i== cf){
            for(int j = 0; j < i; j++)
                add(dp[i][j], dp[i-1][j]);
            for(int j = 0; j < i; j++)
                add(dp[i][j-1], dp[i-1][j] * 1ll * j % mod);
            }   else {

                for(int j = 0; j < i; j++){

                    if(j >= 2)
                        add(dp[i][j-1], dp[i-1][j] * 1ll * j % mod * 1ll * (j-1) % mod);
                    if(i >= cs)
                        add(dp[i][j-1],dp[i-1][j] * 1ll * j % mod);
                     if(i >= cf)
                        add(dp[i][j-1],dp[i-1][j] * 1ll * j % mod);
                    add(dp[i][j+1], dp[i-1][j]);
                }

            }

    }

    cout << dp[n-1][0] << '\n';

    return 0;
}

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 2 ms 608 KB Output is correct
5 Correct 2 ms 688 KB Output is correct
6 Correct 2 ms 768 KB Output is correct
7 Correct 2 ms 788 KB Output is correct
8 Correct 2 ms 788 KB Output is correct
9 Correct 2 ms 796 KB Output is correct
10 Correct 2 ms 800 KB Output is correct
11 Correct 2 ms 804 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 2 ms 608 KB Output is correct
5 Correct 2 ms 688 KB Output is correct
6 Correct 2 ms 768 KB Output is correct
7 Correct 2 ms 788 KB Output is correct
8 Correct 2 ms 788 KB Output is correct
9 Correct 2 ms 796 KB Output is correct
10 Correct 2 ms 800 KB Output is correct
11 Correct 2 ms 804 KB Output is correct
12 Correct 3 ms 1448 KB Output is correct
13 Correct 3 ms 1452 KB Output is correct
14 Correct 3 ms 1456 KB Output is correct
15 Correct 4 ms 1460 KB Output is correct
16 Correct 4 ms 1464 KB Output is correct
17 Correct 4 ms 1488 KB Output is correct
18 Correct 3 ms 1488 KB Output is correct
19 Correct 4 ms 1488 KB Output is correct
20 Correct 3 ms 1508 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 544 KB Output is correct
4 Correct 2 ms 608 KB Output is correct
5 Correct 2 ms 688 KB Output is correct
6 Correct 2 ms 768 KB Output is correct
7 Correct 2 ms 788 KB Output is correct
8 Correct 2 ms 788 KB Output is correct
9 Correct 2 ms 796 KB Output is correct
10 Correct 2 ms 800 KB Output is correct
11 Correct 2 ms 804 KB Output is correct
12 Correct 3 ms 1448 KB Output is correct
13 Correct 3 ms 1452 KB Output is correct
14 Correct 3 ms 1456 KB Output is correct
15 Correct 4 ms 1460 KB Output is correct
16 Correct 4 ms 1464 KB Output is correct
17 Correct 4 ms 1488 KB Output is correct
18 Correct 3 ms 1488 KB Output is correct
19 Correct 4 ms 1488 KB Output is correct
20 Correct 3 ms 1508 KB Output is correct
21 Correct 12 ms 4200 KB Output is correct
22 Correct 13 ms 4432 KB Output is correct
23 Correct 15 ms 5108 KB Output is correct
24 Correct 76 ms 14460 KB Output is correct
25 Correct 75 ms 14464 KB Output is correct
26 Correct 72 ms 14468 KB Output is correct
27 Correct 82 ms 14472 KB Output is correct
28 Correct 48 ms 14472 KB Output is correct