hdu 1023 卡特兰数经典

#include <iostream>
using namespace std;
int a[105][105];
int b[105];
void catalan() //求卡特兰数
{
int i, j, len, carry, temp;
a[1][0] = b[1] = 1;
len = 1;
for(i = 2; i <= 100; i++)
{
for(j = 0; j < len; j++) //乘法
a[i][j] = a[i-1][j]*(4*(i-1)+2);
carry = 0;
for(j = 0; j < len; j++) //处理相乘结果
{
temp = a[i][j] + carry;
a[i][j] = temp % 10;
carry = temp / 10;
}
while(carry) //进位处理
{
a[i][len++] = carry % 10;
carry /= 10;
}
carry = 0;
for(j = len-1; j >= 0; j--) //除法
{
temp = carry*10 + a[i][j];
a[i][j] = temp/(i+1);
carry = temp%(i+1);
}
while(!a[i][len-1]) //高位零处理
len --;
b[i] = len;
}
}
int main(int argc, char *argv[])
{
int n,i;
catalan();
int j;
while (cin >> n)
{
for(j = b
- 1; j >= 0; j--)
{
printf("%d",a
[j]);

}
printf("\n");

}
return 0;
}