/*If we keep holding onto yesterday, what are we going to be tomorrow?*/
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define int long long int
#define dbg if(debugg)
#define F first
#define S second
bool debugg = false;
template <typename T>
using order_set = tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update>;
template <typename T>
using minheap = priority_queue<T, vector<T>, greater<T>>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int mod = 1000000007;
int n, s, e;
int dp[2002][2002];
void solve()
{
cin >> n >> s >> e;
dp[1][1] = 1;
for(int i = 2; i <= n; i ++){
for(int j = 1; j <= n; j ++){
if(i == s || i == e){
dp[i][j] = (dp[i - 1][j] + dp[i - 1][j - 1]) % mod;
}
else{
int x = (dp[i - 1][j + 1] * j) % mod;
int y = (dp[i - 1][j - 1] * (j - (i > s) - (i > e))) % mod;
dp[i][j] = (x + y) % mod;
}
}
}
cout << dp[n][1] << '\n';
}
int32_t main()
{
ios::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
while(t--){
solve();
}
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
1 ms |
2396 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Correct |
1 ms |
2396 KB |
Output is correct |
7 |
Correct |
1 ms |
2396 KB |
Output is correct |
8 |
Correct |
1 ms |
2396 KB |
Output is correct |
9 |
Correct |
1 ms |
2396 KB |
Output is correct |
10 |
Correct |
1 ms |
2392 KB |
Output is correct |
11 |
Correct |
1 ms |
2392 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
1 ms |
2396 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Correct |
1 ms |
2396 KB |
Output is correct |
7 |
Correct |
1 ms |
2396 KB |
Output is correct |
8 |
Correct |
1 ms |
2396 KB |
Output is correct |
9 |
Correct |
1 ms |
2396 KB |
Output is correct |
10 |
Correct |
1 ms |
2392 KB |
Output is correct |
11 |
Correct |
1 ms |
2392 KB |
Output is correct |
12 |
Correct |
1 ms |
4444 KB |
Output is correct |
13 |
Correct |
1 ms |
4444 KB |
Output is correct |
14 |
Correct |
1 ms |
4444 KB |
Output is correct |
15 |
Correct |
1 ms |
4444 KB |
Output is correct |
16 |
Correct |
1 ms |
4444 KB |
Output is correct |
17 |
Correct |
1 ms |
4600 KB |
Output is correct |
18 |
Correct |
1 ms |
4444 KB |
Output is correct |
19 |
Correct |
1 ms |
4444 KB |
Output is correct |
20 |
Correct |
1 ms |
4444 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
2396 KB |
Output is correct |
4 |
Correct |
1 ms |
2396 KB |
Output is correct |
5 |
Correct |
1 ms |
2396 KB |
Output is correct |
6 |
Correct |
1 ms |
2396 KB |
Output is correct |
7 |
Correct |
1 ms |
2396 KB |
Output is correct |
8 |
Correct |
1 ms |
2396 KB |
Output is correct |
9 |
Correct |
1 ms |
2396 KB |
Output is correct |
10 |
Correct |
1 ms |
2392 KB |
Output is correct |
11 |
Correct |
1 ms |
2392 KB |
Output is correct |
12 |
Correct |
1 ms |
4444 KB |
Output is correct |
13 |
Correct |
1 ms |
4444 KB |
Output is correct |
14 |
Correct |
1 ms |
4444 KB |
Output is correct |
15 |
Correct |
1 ms |
4444 KB |
Output is correct |
16 |
Correct |
1 ms |
4444 KB |
Output is correct |
17 |
Correct |
1 ms |
4600 KB |
Output is correct |
18 |
Correct |
1 ms |
4444 KB |
Output is correct |
19 |
Correct |
1 ms |
4444 KB |
Output is correct |
20 |
Correct |
1 ms |
4444 KB |
Output is correct |
21 |
Correct |
5 ms |
10588 KB |
Output is correct |
22 |
Correct |
4 ms |
12636 KB |
Output is correct |
23 |
Correct |
4 ms |
12888 KB |
Output is correct |
24 |
Correct |
23 ms |
31580 KB |
Output is correct |
25 |
Correct |
20 ms |
31580 KB |
Output is correct |
26 |
Correct |
19 ms |
31640 KB |
Output is correct |
27 |
Correct |
19 ms |
31576 KB |
Output is correct |
28 |
Correct |
12 ms |
25180 KB |
Output is correct |