BZOJ 2431 逆序对数列

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxn 1050
#define mod 10000
using namespace std;
int t,n[15],k[15],mn=0,mk=0,f[maxn][maxn],g[maxn][maxn];
int main()
{
    scanf("%d%d",&mn,&mk);
    f[0][0]=1;for (int i=0;i<=mk;i++) g[0][i]=1;
    for (int i=1;i<=mn;i++)
    {
        for (int j=0;j<=mk;j++)
        {
            if (j>i-1) f[i][j]=g[i-1][j]-g[i-1][j-i];
            else f[i][j]=g[i-1][j];
            f[i][j]=(f[i][j]+mod)%mod;
        }
        g[i][0]=f[i][0];
        for (int j=1;j<=mk;j++) g[i][j]=(g[i][j-1]+f[i][j])%mod;
    }
    printf("%d\n",f[mn][mk]%mod);
    return 0;
}