oj.uz

Submission #493910

# Submission time Handle Problem Language Result Execution time Memory
493910 2021-12-13T10:54:47 Z khoabright Kangaroo (CEOI16_kangaroo) C++17
100 / 100
 35 ms 31608 KB 
#include <bits/stdc++.h>
using namespace std;

#define int long long 
#define ll long long
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back
#define rep(i, a, b) for (int i = (int)a; i <= (int)b; ++i)
#define rep1(i, a, b) for (int i = (int)a; i >= (int)b; --i)
#define all(x) x.begin(), x.end()

const int N = 2e3 + 5;
const int mod = 1e9 + 7;

int dp[N][N];

main() {
    int n, a, b; cin >> n >> a >> b;
    dp[1][1] = 1;
    rep(i, 1, n - 1) rep(j, 1, n) {
        if (i + 1 == a || i + 1 == b) {
            (dp[i + 1][j] += dp[i][j]) %= mod;
            (dp[i + 1][j + 1] += dp[i][j]) %= mod;
        }

        else {
            // merge two components
            (dp[i + 1][j - 1] += dp[i][j] * (j - 1)) %= mod;

            // create a new component
            (dp[i + 1][j + 1] += (dp[i][j] * (j + 1 - (i + 1 > a) - (i + 1 > b)))) %= mod;
        }
    }

    cout << dp[n][1];
}

Compilation message

kangaroo.cpp:19:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   19 | main() {
      | ^~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 424 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 424 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 424 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 424 KB Output is correct
12 Correct 1 ms 1356 KB Output is correct
13 Correct 1 ms 1228 KB Output is correct
14 Correct 1 ms 1356 KB Output is correct
15 Correct 1 ms 1356 KB Output is correct
16 Correct 1 ms 1356 KB Output is correct
17 Correct 1 ms 1356 KB Output is correct
18 Correct 1 ms 1228 KB Output is correct
19 Correct 1 ms 1356 KB Output is correct
20 Correct 1 ms 1356 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 0 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 424 KB Output is correct
5 Correct 1 ms 460 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 1 ms 460 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 460 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 424 KB Output is correct
12 Correct 1 ms 1356 KB Output is correct
13 Correct 1 ms 1228 KB Output is correct
14 Correct 1 ms 1356 KB Output is correct
15 Correct 1 ms 1356 KB Output is correct
16 Correct 1 ms 1356 KB Output is correct
17 Correct 1 ms 1356 KB Output is correct
18 Correct 1 ms 1228 KB Output is correct
19 Correct 1 ms 1356 KB Output is correct
20 Correct 1 ms 1356 KB Output is correct
21 Correct 6 ms 6324 KB Output is correct
22 Correct 6 ms 6860 KB Output is correct
23 Correct 7 ms 7756 KB Output is correct
24 Correct 31 ms 31608 KB Output is correct
25 Correct 34 ms 31556 KB Output is correct
26 Correct 35 ms 31572 KB Output is correct
27 Correct 34 ms 31416 KB Output is correct
28 Correct 28 ms 23760 KB Output is correct