Lähetit

#include <iostream>
#define F first
#define S second
using namespace std;
typedef long long ll;

ll dp[211][211][211];
const ll mod=1e9+7;

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n,k;
    cin>>n>>k;
    dp[0][0][0]=1;
    if (k>n*2){
        cout<<0<<endl;
        return 0;
    }
    for (int i=0;i<2*n-1;i++){
        for (int ii=0;ii<=k;ii++){
            for (int iii=0;iii<=k;iii++){
                if (dp[i][ii][iii]&&ii+iii<=k){
                    ll tv=dp[i][ii][iii];
                    int t=1+i/2;
                    dp[i+1][ii][iii]+=tv;
                    dp[i+1][ii][iii]%=mod;
                    if (t%2==1){
                        if (t-ii>0){
                            dp[i+1][ii+1][iii]+=tv*(ll)(t-ii);
                            dp[i+1][ii+1][iii]%=mod;
                        }
                    }
                    else{
                        if (t-iii>0){
                            dp[i+1][ii][iii+1]+=tv*(ll)(t-iii);
                            dp[i+1][ii][iii+1]%=mod;
                        }
                    }
                }
            }
        }
    }
    ll v=0;
    for (int i=0;i<=k;i++){
        for (int ii=0;ii<=k;ii++){
            if (i+ii==k){
                v+=dp[2*n-1][i][ii];
                v%=mod;
            }
        }
    }
    cout<<v<<endl;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED