50求助

#include<cstring>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<algorithm>
#define now f[i][j][k]
using namespace std;
inline int read()
{
    register int X=0;
    register char ch=0;
    bool flag=0;
    for(; !isdigit(ch); ch=getchar()) if(ch=='-') flag=1;
    for(; isdigit(ch); ch=getchar()) X=(X<<3)+(X<<1)+ch-'0';
    return (flag ? -X : X);
}
int N=101;const long long mod=9999973;
int n,m;
long long f[101][101][101],ans;
int C(int x)
{
    return x*(x-1)/2;
}
int main()
{
    n=read(),m=read();
    f[0][0][0]=1;
    for(int i=0; i<n; i++)
        for(int j=0; j<=m; j++)
            for(int k=0; k+j<=n; k++)
                if(now)
                {
                    (f[i+1][j][k]+=now)%=mod;
                    if(m-j-k > 0) (f[i+1][j+1][k]+=now*(m-j-k))%=mod;
                    if(m-j-k > 1) (f[i+1][j+2][k]+=now*C(m-j-k))%=mod;
                    if(j > 0) (f[i+1][j-1][k+1]+=now*j)%=mod;
                    if(j > 0 && m-j-k > 0) (f[i+1][j][k+1]+=now*j*(m-j-k))%=mod;
                    if(j > 1) (f[i+1][j-2][k+2]+=now*C(j))%=mod;
                }
	for(int i=0;i<=m;i++)
		for(int j=0;j+i<=m;j++)
			(ans+=f[n][i][j])%=mod;
	printf("%lld\n",ans);
}