Submission #871351
Source Code Expand
//#pragma comment(linker, "/STACK:102400000,102400000")
#include <fstream>
#include <iostream>
#include <functional>
#include <algorithm>
#include <cstring>
#include <vector>
#include <string>
#include <cstdio>
#include <cmath>
#include <queue>
#include <stack>
#include <deque>
#include <ctime>
#include <list>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
#define eps 1e-10
#define LL_INF 0x33ffffffffffffff
#define INF 0x3f3f3f3f
#define mem(a, b) memset(a, b, sizeof(a))
#define pper(i,n,m) for(int i = n;i >= m; i--)
#define repp(i, n, m) for (int i = n; i <= m; i++)
#define rep(i, n, m) for (int i = n; i < m; i++)
#define sa(n) scanf("%d", &(n))
#define mp make_pair
#define ff first
#define ss second
#define pb push_back
const int maxn = 4e6 + 5;
const double PI = acos(-1.0);
const ll mod = 1e9 + 7;
ll po(ll a, ll b,ll mod) { ll res = 1; a %= mod; for (; b; b >>= 1) { if (b & 1)res = res*a%mod; a = a*a%mod; }return res; }
ll gcd(ll a,ll b){ if(a==0){return b;}else{ return gcd(b%a,a);}}
ll n,k;
ll fac[maxn],inv[maxn];
ll dp[2005][2005];
ll C(ll n,ll x)
{
return fac[n]*inv[x]%mod*inv[n-x]%mod;
}
void init()
{
fac[0]=1;
inv[0]=1;
ll up = 4e6;
for(ll i=1;i <= up;i++)
{
fac[i]=fac[i-1]*i%mod;
inv[i]=po(fac[i],mod-2,mod);
}
}
ll cal(ll i,ll j)
{
if(dp[i][j]!=-1)
{
return dp[i][j];
}
ll res=0;
if(i==0&&j==0)
{
return 1;
}
if(j > i)
{
res += C(i+j*(k-1)-1,k-2)*cal(i,j-1)%mod;
}
res%=mod;
if(i)
{
res += cal(i-1,j);
}
res%=mod;
dp[i][j]=res;
return res;
}
void solve()
{
memset(dp,-1,sizeof(dp));
cin>>n>>k;
if(k==1)
{
cout<<1<<endl;
return;
}
ll res= cal(n,n);
for(ll i=1;i<=n;i++)
{
res=res*i%mod;
}
cout<<res<<endl;
}
int main()
{
init();
solve();
return 0;
}
Submission Info
Submission Time |
|
Task |
F - Leftmost Ball |
User |
wangchong756 |
Language |
C++14 (GCC 5.4.1) |
Score |
1600 |
Code Size |
1875 Byte |
Status |
AC |
Exec Time |
1500 ms |
Memory |
94336 KB |
Judge Result
Set Name |
Sample |
All |
Score / Max Score |
0 / 0 |
1600 / 1600 |
Status |
|
|
Set Name |
Test Cases |
Sample |
0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt |
All |
0_00.txt, 0_01.txt, 0_02.txt, 0_03.txt, 1_00.txt, 1_01.txt, 1_02.txt, 1_03.txt, 1_04.txt, 1_05.txt, 1_06.txt, 1_07.txt, 1_08.txt, 1_09.txt, 1_10.txt, 1_11.txt, 1_12.txt, 1_13.txt, 1_14.txt, 1_15.txt, 1_16.txt, 1_17.txt, 1_18.txt, 1_19.txt |
Case Name |
Status |
Exec Time |
Memory |
0_00.txt |
AC |
1391 ms |
94080 KB |
0_01.txt |
AC |
1387 ms |
94080 KB |
0_02.txt |
AC |
1384 ms |
94080 KB |
0_03.txt |
AC |
1500 ms |
94336 KB |
1_00.txt |
AC |
1387 ms |
94208 KB |
1_01.txt |
AC |
1405 ms |
94208 KB |
1_02.txt |
AC |
1386 ms |
94208 KB |
1_03.txt |
AC |
1500 ms |
94336 KB |
1_04.txt |
AC |
1489 ms |
94336 KB |
1_05.txt |
AC |
1482 ms |
94336 KB |
1_06.txt |
AC |
1477 ms |
94336 KB |
1_07.txt |
AC |
1471 ms |
94336 KB |
1_08.txt |
AC |
1472 ms |
94336 KB |
1_09.txt |
AC |
1488 ms |
94336 KB |
1_10.txt |
AC |
1472 ms |
94336 KB |
1_11.txt |
AC |
1497 ms |
94336 KB |
1_12.txt |
AC |
1413 ms |
94208 KB |
1_13.txt |
AC |
1471 ms |
94336 KB |
1_14.txt |
AC |
1403 ms |
94208 KB |
1_15.txt |
AC |
1403 ms |
94208 KB |
1_16.txt |
AC |
1437 ms |
94208 KB |
1_17.txt |
AC |
1470 ms |
94336 KB |
1_18.txt |
AC |
1397 ms |
94208 KB |
1_19.txt |
AC |
1495 ms |
94336 KB |