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Submission #527812

# Submission time Handle Problem Language Result Execution time Memory
527812 2022-02-18T11:58:12 Z Monarchuwu Kangaroo (CEOI16_kangaroo) C++17
100 / 100
 20 ms 22988 KB 
/**
 *  Problem:    CEOI16_kangaroo - Kangaroo
 *  Link:       https://oj.uz/problem/view/CEOI16_kangaroo
 *  Tags:       DP CC
**/
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;

const int N = 2000 + 3, mod = 1e9 + 7;
int n, cs, cf;

#define add(a, b) (a += b) %= mod
ll dp[N][N];
int main() {
    cin.tie(NULL)->sync_with_stdio(false);
    cin >> n >> cs >> cf;
    if (cs > cf) cs = n - cs + 1, cf = n - cf + 1;

    dp[1][1] = 1;
    for (int i = 2; i <= n; ++i)
        for (int j = 1; j < i; ++j) if (dp[i - 1][j]) {
            if (cs == i) {
                add(dp[i][j + 1], dp[i - 1][j]); // nhảy sang phải
                add(dp[i][j + 0], dp[i - 1][j]); // nhảy sang trái
                continue;
            }

            if (cf == i) {
                add(dp[i][j + 1], dp[i - 1][j]); // đến từ phải
                add(dp[i][j + 0], dp[i - 1][j]); // đến từ trái
                continue;
            }

            add(dp[i][j + 1], dp[i - 1][j] * (j - (cs < i) - (cf < i) + 1));
            add(dp[i][j - 1], dp[i - 1][j] * (j - 1));
        }

    cout << dp[n][1] << '\n';
}
/**  /\_/\
 *  (= ._.)
 *  / >0  \>1
**/

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 1 ms 320 KB Output is correct
4 Correct 0 ms 460 KB Output is correct
5 Correct 1 ms 440 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 0 ms 448 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 460 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 1 ms 320 KB Output is correct
4 Correct 0 ms 460 KB Output is correct
5 Correct 1 ms 440 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 0 ms 448 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 460 KB Output is correct
12 Correct 1 ms 1228 KB Output is correct
13 Correct 1 ms 1100 KB Output is correct
14 Correct 1 ms 1228 KB Output is correct
15 Correct 1 ms 1228 KB Output is correct
16 Correct 1 ms 1228 KB Output is correct
17 Correct 1 ms 1228 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 1 ms 1228 KB Output is correct
20 Correct 2 ms 1228 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 1 ms 320 KB Output is correct
4 Correct 0 ms 460 KB Output is correct
5 Correct 1 ms 440 KB Output is correct
6 Correct 1 ms 460 KB Output is correct
7 Correct 0 ms 448 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 460 KB Output is correct
12 Correct 1 ms 1228 KB Output is correct
13 Correct 1 ms 1100 KB Output is correct
14 Correct 1 ms 1228 KB Output is correct
15 Correct 1 ms 1228 KB Output is correct
16 Correct 1 ms 1228 KB Output is correct
17 Correct 1 ms 1228 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 1 ms 1228 KB Output is correct
20 Correct 2 ms 1228 KB Output is correct
21 Correct 3 ms 4556 KB Output is correct
22 Correct 4 ms 4940 KB Output is correct
23 Correct 4 ms 5512 KB Output is correct
24 Correct 19 ms 22988 KB Output is correct
25 Correct 19 ms 22964 KB Output is correct
26 Correct 19 ms 22956 KB Output is correct
27 Correct 20 ms 22844 KB Output is correct
28 Correct 12 ms 15132 KB Output is correct