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Submission #999579

# Submission time Handle Problem Language Result Execution time Memory
999579 2024-06-15T20:30:22 Z codefox Kangaroo (CEOI16_kangaroo) C++14
100 / 100
 49 ms 31836 KB 
#include<bits/stdc++.h>

using namespace std;

#define int long long
int mod = 1e9+7;

int32_t main()
{
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    int n, a, b;
    cin >> n >> a >> b;
    vector<vector<int>> dp(n+1, vector<int>(n+1, 0));
    dp[1][1] = 1;
    int bb = 0;
    if (a==1) bb++;
    if (b==1) bb++;
    for (int i = 2; i <= n; i++)
    {
        if (i==a) 
        {
            dp[i] = vector<int>(dp[i-1]);
            i++;
            bb++;
        }
        if (i==b)
        {
            if (n%2==0)
            {
                for (int j = 2; j <= n; j++)
                {
                    dp[i][j] += dp[i-1][j-1];
                }
            }
            else
            {
                dp[i] = vector<int>(dp[i-1]);
            }
            i++;
            bb++;
        }
        if (i==a) 
        {
            dp[i] = vector<int>(dp[i-1]);
            i++;
            bb++;
        }
        if (i>n) break;
        for (int j = 2; j <=n; j++)
        {
            dp[i][j] += dp[i-1][j-1]*(j);
            dp[i][j] -= dp[i-1][j-1]*bb;
            dp[i][j-1] += dp[i-1][j]*(j-1);
        }
        for (int j = 1; j <= n; j++) dp[i][j]%=mod;
    }
    int sol = dp[n][1];
    dp.assign(n+1, vector<int>(n+1, 0));
    dp[1][1] =1;
    bb=0;
    if (a==1) bb++;
    if (b==1) bb++;
    for (int i = 2; i <= n; i++)
    {
        if (i==a) 
        {
            for (int j = 2; j <= n; j++)
            {
                dp[i][j] += dp[i-1][j-1];
            }
            i++;
            bb++;
        }
        if (i==b)
        {
            if (n%2)
            {
                for (int j = 2; j <= n; j++)
                {
                    dp[i][j] += dp[i-1][j-1];
                }
            }
            else
            {
                dp[i] = vector<int>(dp[i-1]);
            }
            i++;
            bb++;
        }
        if (i==a) 
        {
            for (int j = 2; j <= n; j++)
            {
                dp[i][j] += dp[i-1][j-1];
            }
            i++;
            bb++;
        }
        if (i>n) break;
        for (int j = 2; j <=n; j++)
        {
            dp[i][j] += dp[i-1][j-1]*(j);
            dp[i][j] -= dp[i-1][j-1]*bb;
            dp[i][j-1] += dp[i-1][j]*(j-1);
        }
        for (int j = 1; j <= n; j++) dp[i][j]%=mod;
    }
    cout << (sol + dp[n][1])%mod;
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory 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

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 600 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 600 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 604 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 1 ms 604 KB Output is correct
16 Correct 1 ms 604 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Correct 1 ms 604 KB Output is correct
19 Correct 1 ms 604 KB Output is correct
20 Correct 1 ms 604 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 0 ms 604 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 1 ms 348 KB Output is correct
7 Correct 1 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 600 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 604 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 1 ms 604 KB Output is correct
16 Correct 1 ms 604 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Correct 1 ms 604 KB Output is correct
19 Correct 1 ms 604 KB Output is correct
20 Correct 1 ms 604 KB Output is correct
21 Correct 5 ms 3676 KB Output is correct
22 Correct 6 ms 4272 KB Output is correct
23 Correct 6 ms 4784 KB Output is correct
24 Correct 44 ms 31836 KB Output is correct
25 Correct 49 ms 31832 KB Output is correct
26 Correct 47 ms 31836 KB Output is correct
27 Correct 45 ms 31580 KB Output is correct
28 Correct 26 ms 18064 KB Output is correct