hdu 1133 Buy the Ticket

#include <stdio.h>
#include <string.h>

const int N=101,base=10000000;
int f

;
void plus(int *a,int *b)
{
int i;
if (b[0]>a[0]) a[0]=b[0];
for (i=1;i<=a[0];i++)
{
a[i]+=b[i];
if (a[i]>=base)
{
a[i]-=base;
a[i+1]++;
}
if (a[a[0]+1]>0) a[0]++;
}
}
void mult(int *a,int b)
{
int i;
a[1]*=b;
for (i=2;i<=a[0];i++)
{
a[i]=a[i]*b+a[i-1]/base;
a[i-1]%=base;
}
while (a[a[0]]>=base)
{
a[0]++;
a[a[0]]=a[a[0]-1]/base;
a[a[0]-1]%=base;
}
}
void printbn(int *a)
{
int i;
printf("%d",a[a[0]]);
for (i=a[0]-1;i>0;i--) printf("%07d",a[i]);
printf("\n");
}
int main()
{
int i,j,k;
memset(f,0,sizeof(f));
for (i=1;i<N;i++) f[i][0][0]=f[i][0][1]=1;
for (i=1;i<N;i++)
for (j=1;j<=i;j++)
{
plus(f[i][j],f[i-1][j]);
plus(f[i][j],f[i][j-1]);
}
for (i=0;i<N;i++)
for (j=0;j<=i;j++)
{
for (k=1;k<=i;k++) mult(f[i][j],k);
for (k=1;k<=j;k++) mult(f[i][j],k);
}
int c=0,n,m;
while (scanf("%d%d",&n,&m) && (n||m))
{
printf("Test #%d:\n",++c);
printbn(f
[m]);
}
return 0;
}