#include<iostream>
using namespace std;
int a[101][101]={0};
int main()
{
intn,i,j,len,r,temp,t;
intb[101];
a[1][0] =1;
len =1;
b[1] =1;
for(i=2;i<=100;i++)
{
t = i-1;
for(j=0;j<len;j++) //乘法
a[i][j] = a[i-1][j]*(4*t+2);
for(r=j=0;j<len;j++)//处理相乘结果
{
t emp = a[i][j] + r;
a[i][j] = temp % 10;
r = temp / 10;
}
while(r) //进位处理
{
a[i][len++] = r % 10;
r /= 10;
}
for(j=len-1,r=0;j>=0;j--) //除法
{
temp = r*10 + a[i][j];
a[i][j] = temp/(t+2);
r = temp%(t+2);
}
while(!a[i][len-1]) //高位零处理
len --;
b[i] = len;
}
while(cin>>n)
{
for(j=b[n]-1;j>=0;j--)
printf("%d",a[n][j]);
![hdu1023 501023](http://img.aihuau.com/images/01111101/01080931t01e41e5c7c64f323fe.png)
printf("n");
}
return0;
}