oj.uz

Submission #307653

# Submission time Handle Problem Language Result Execution time Memory
307653 2020-09-29T01:11:34 Z Elephant52 Kangaroo (CEOI16_kangaroo) C++11
100 / 100
 63 ms 31608 KB 
#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pair<int, int> > vpi;

#define INF 1000000000
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define rep(i,a,b) for (ll i = a; i < b; i++)

void setIO(string name) {
    freopen((name+".in").c_str(), "r", stdin); 
    freopen((name+".out").c_str(), "w", stdout);
}

int N, A, B;

int mod = 1e9 + 7;

ll dp[2001][2001];

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

    cin >> N >> A >> B;
    
    dp[1][1] = 1;
    
    rep(i,2,N+1) {
        rep(j,1,N+1) {
            if (i == A || i == B) dp[i][j] = (dp[i-1][j] + dp[i-1][j-1]) % mod;
            else dp[i][j] = j * dp[i-1][j+1] % mod + dp[i-1][j-1] * (j - (i > A) - (i > B)) % mod;
        }
    }
    
    cout << dp[N][1] << endl;
       
    return 0;
}

Compilation message

kangaroo.cpp: In function 'void setIO(std::string)':
kangaroo.cpp:18:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   18 |     freopen((name+".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp:19:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   19 |     freopen((name+".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 0 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 0 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 0 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 0 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 1 ms 1408 KB Output is correct
13 Correct 1 ms 1408 KB Output is correct
14 Correct 1 ms 1408 KB Output is correct
15 Correct 1 ms 1408 KB Output is correct
16 Correct 2 ms 1408 KB Output is correct
17 Correct 1 ms 1408 KB Output is correct
18 Correct 1 ms 1280 KB Output is correct
19 Correct 1 ms 1408 KB Output is correct
20 Correct 1 ms 1408 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 512 KB Output is correct
6 Correct 0 ms 512 KB Output is correct
7 Correct 1 ms 512 KB Output is correct
8 Correct 0 ms 512 KB Output is correct
9 Correct 1 ms 512 KB Output is correct
10 Correct 1 ms 512 KB Output is correct
11 Correct 1 ms 512 KB Output is correct
12 Correct 1 ms 1408 KB Output is correct
13 Correct 1 ms 1408 KB Output is correct
14 Correct 1 ms 1408 KB Output is correct
15 Correct 1 ms 1408 KB Output is correct
16 Correct 2 ms 1408 KB Output is correct
17 Correct 1 ms 1408 KB Output is correct
18 Correct 1 ms 1280 KB Output is correct
19 Correct 1 ms 1408 KB Output is correct
20 Correct 1 ms 1408 KB Output is correct
21 Correct 9 ms 6400 KB Output is correct
22 Correct 10 ms 6912 KB Output is correct
23 Correct 11 ms 7808 KB Output is correct
24 Correct 63 ms 31608 KB Output is correct
25 Correct 62 ms 31608 KB Output is correct
26 Correct 62 ms 31608 KB Output is correct
27 Correct 62 ms 31480 KB Output is correct
28 Correct 38 ms 23800 KB Output is correct