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Submission #985551

# Submission time Handle Problem Language Result Execution time Memory
985551 2024-05-18T07:28:14 Z Blistering_Barnacles Kangaroo (CEOI16_kangaroo) C++17
100 / 100
 15 ms 15964 KB 
//Billions of bilious blue blistering barnacles in a thundering typhoon!
//Yesterday is history, tomorrow is a mystery, today is a gift of God, which is why we call it the present.
#include<bits/stdc++.h>
using namespace std;
void solve(){
    const int mod = (int)1e9 + 7;
    auto add = [&](int x, int y) -> int{
        return x + y - (x + y >= mod) * mod;
    };
    auto mul = [&](int x, int y) -> int{
        return (int64_t)x * y % mod;
    };
    int n, s, e;
    cin >> n >> s >> e;
    vector<vector<int>> dp(n + 1, vector<int>(n + 1, 0));
    dp[1][1] = 1;
    for(int i = 2; i <= n; i++){
        for(int j = 1; j <= i; j++){
            if(i == s){
                //either make a new component on the left or stick it to the leftmost component
                dp[i][j] = add(dp[i - 1][j - 1], dp[i - 1][j]);
            }
            else if(i == e){
                //either make a new component on the right or stick it to the rightmost component
                dp[i][j] = add(dp[i - 1][j - 1], dp[i - 1][j]);
            }
            else{
                //either make a new component or merge to components 
                //num is the number of places to make a new component
                int num = j - (i > s) - (i > e);
                dp[i][j] = add(mul(num, dp[i - 1][j - 1]), mul(j, dp[i - 1][j + 1]));
            }
        }
    }
    cout << dp[n][1] << "\n";
}
int main(){
    ios::sync_with_stdio(0), cin.tie(0);
    int tt = 1;
    //cin >> tt;
    while(tt--){
        solve();
    }
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 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 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 600 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 600 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 604 KB Output is correct
13 Correct 1 ms 592 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 1 ms 600 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 348 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 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 344 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 600 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 604 KB Output is correct
13 Correct 1 ms 592 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 1 ms 600 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 348 KB Output is correct
19 Correct 1 ms 604 KB Output is correct
20 Correct 1 ms 604 KB Output is correct
21 Correct 2 ms 2136 KB Output is correct
22 Correct 2 ms 2396 KB Output is correct
23 Correct 2 ms 2504 KB Output is correct
24 Correct 15 ms 15964 KB Output is correct
25 Correct 15 ms 15964 KB Output is correct
26 Correct 15 ms 15964 KB Output is correct
27 Correct 15 ms 15828 KB Output is correct
28 Correct 8 ms 9308 KB Output is correct