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Submission #642477

# Submission time Handle Problem Language Result Execution time Memory
642477 2022-09-19T14:27:31 Z BackNoob Kangaroo (CEOI16_kangaroo) C++14
100 / 100
 31 ms 15964 KB 
#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1)
#define TASK "task"
#define sz(s) (int) (s).size()
 
using namespace std;
const int mxN = 2008;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 307;
const int LOG = 20;
 
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
    if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
    if (a < b) {a = b; return true;} return false;
}

int n;
int sta;
int fin;
int dp[mxN][mxN];

void add(int &a, int b)
{
    a += b;
    if(a >= mod)
        a -= mod;
}

void solve()
{
    cin >> n >> sta >> fin;
    dp[1][1] = 1;

    for(int i = 2; i <= n; i++) {
        for(int j = 1; j <= n; j++) {
            if(i == sta || i == fin) {
                add(dp[i][j], dp[i - 1][j - 1]);
                add(dp[i][j], dp[i - 1][j]);
            }
            else {
                add(dp[i][j], 1LL * dp[i - 1][j + 1] * j % mod);
                add(dp[i][j], 1LL * dp[i - 1][j - 1] * (j - (i > sta) - (i > fin)) % mod);
            }
        }
    }

    cout << dp[n][1];
}
 
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

 
    int tc = 1;
    //cin >> tc;
    while(tc--) {
        solve();
    }
    return 0;
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 468 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 1228 KB Output is correct
13 Correct 1 ms 1104 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 1224 KB Output is correct
17 Correct 1 ms 1236 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 2 ms 1236 KB Output is correct
20 Correct 1 ms 1232 KB Output is correct

Subtask #4
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 468 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 0 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 460 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 1228 KB Output is correct
13 Correct 1 ms 1104 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 1224 KB Output is correct
17 Correct 1 ms 1236 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 2 ms 1236 KB Output is correct
20 Correct 1 ms 1232 KB Output is correct
21 Correct 5 ms 4564 KB Output is correct
22 Correct 5 ms 4948 KB Output is correct
23 Correct 6 ms 5500 KB Output is correct
24 Correct 29 ms 15964 KB Output is correct
25 Correct 28 ms 15916 KB Output is correct
26 Correct 28 ms 15928 KB Output is correct
27 Correct 31 ms 15944 KB Output is correct
28 Correct 26 ms 12028 KB Output is correct