oj.uz

Submission #44782

# Submission time Handle Problem Language Result Execution time Memory
44782 2018-04-06T11:24:25 Z bogdan10bos Kangaroo (CEOI16_kangaroo) C++14
100 / 100
 24 ms 14464 KB 
#include <bits/stdc++.h>

using namespace std;

//#define FILE_IO

const int mod = 1e9 + 7;

int dp[2005][2005];

int main()
{
    #ifdef FILE_IO
    freopen("1.in", "r", stdin);
    freopen("1.out", "w", stdout);
    #endif

    int N, st, fn;
    scanf("%d%d%d", &N, &st, &fn);

    dp[1][1] = 1;
    int ends = 2;
    if(st == 1 || fn == 1)  ends--;
    for(int i = 2; i <= N; i++)
    {
        if(i == st || i == fn)
        {
            for(int j = 1; j <= i; j++)
                dp[i][j] = (dp[i - 1][j] + dp[i - 1][j - 1]) % mod;
            ends--;
            continue;
        }

        for(int j = 1; j <= i; j++)
        {
            dp[i][j] = 0;
            if(j - 2 + ends >= 0)
                dp[i][j] = (1LL * dp[i - 1][j - 1] * (j - 2 + ends)) % mod;
            dp[i][j] += (1LL * dp[i - 1][j + 1] * j) % mod;
            dp[i][j] %= mod;
        }
    }

    printf("%d\n", dp[N][1]);

    return 0;
}

Compilation message

kangaroo.cpp: In function 'int main()':
kangaroo.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &N, &st, &fn);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 460 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 2 ms 560 KB Output is correct
5 Correct 2 ms 596 KB Output is correct
6 Correct 2 ms 672 KB Output is correct
7 Correct 2 ms 848 KB Output is correct
8 Correct 2 ms 848 KB Output is correct
9 Correct 2 ms 848 KB Output is correct
10 Correct 3 ms 848 KB Output is correct
11 Correct 2 ms 848 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 2 ms 560 KB Output is correct
5 Correct 2 ms 596 KB Output is correct
6 Correct 2 ms 672 KB Output is correct
7 Correct 2 ms 848 KB Output is correct
8 Correct 2 ms 848 KB Output is correct
9 Correct 2 ms 848 KB Output is correct
10 Correct 3 ms 848 KB Output is correct
11 Correct 2 ms 848 KB Output is correct
12 Correct 3 ms 1380 KB Output is correct
13 Correct 2 ms 1380 KB Output is correct
14 Correct 2 ms 1380 KB Output is correct
15 Correct 2 ms 1380 KB Output is correct
16 Correct 2 ms 1380 KB Output is correct
17 Correct 2 ms 1380 KB Output is correct
18 Correct 2 ms 1380 KB Output is correct
19 Correct 2 ms 1384 KB Output is correct
20 Correct 3 ms 1384 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 460 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 2 ms 560 KB Output is correct
5 Correct 2 ms 596 KB Output is correct
6 Correct 2 ms 672 KB Output is correct
7 Correct 2 ms 848 KB Output is correct
8 Correct 2 ms 848 KB Output is correct
9 Correct 2 ms 848 KB Output is correct
10 Correct 3 ms 848 KB Output is correct
11 Correct 2 ms 848 KB Output is correct
12 Correct 3 ms 1380 KB Output is correct
13 Correct 2 ms 1380 KB Output is correct
14 Correct 2 ms 1380 KB Output is correct
15 Correct 2 ms 1380 KB Output is correct
16 Correct 2 ms 1380 KB Output is correct
17 Correct 2 ms 1380 KB Output is correct
18 Correct 2 ms 1380 KB Output is correct
19 Correct 2 ms 1384 KB Output is correct
20 Correct 3 ms 1384 KB Output is correct
21 Correct 5 ms 4068 KB Output is correct
22 Correct 6 ms 4348 KB Output is correct
23 Correct 7 ms 4872 KB Output is correct
24 Correct 23 ms 14380 KB Output is correct
25 Correct 24 ms 14464 KB Output is correct
26 Correct 23 ms 14464 KB Output is correct
27 Correct 23 ms 14464 KB Output is correct
28 Correct 15 ms 14464 KB Output is correct