hdu 1130 How Many Trees?（卡特兰数）

卡特兰数高精度。

/*
Author:Zhaofa Fang
Lang:C++
*/
#include <cstdio>
#include <cstdlib>
#include <sstream>
#include <iostream>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <string>
#include <utility>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
using namespace std;

typedef long long ll;
#define DEBUG(x) cout<< #x << ':' << x << endl
#define REP(i,n) for(int i=0;i < (n);i++)
#define FOR(i,s,t) for(int i = (s);i <= (t);i++)
#define PII pair<int,int>
#define PB push_back
#define MP make_pair
#define ft first
#define sd second
#define lowbit(x) (x&(-x))
#define INF (1<<30)


int f[105][200];
void product(int a[],int b[],int c[])
{
    REP(j,200)c[j]=0;
    int e = 0;
    int N = 200-1;
    while(N>=0 && !b[N] )N--;
    REP(k,N+1)
    {
        for(int j=0;j+k<200;j++)
        {
            int tmp = a[j] * b[k];
            int tmp1 = tmp + c[j+k] + e;
            c[j+k] = (tmp1)%10;
            e = (tmp1)/10;
        }
    }
}
void print(int a[])
{
    int k = 200 - 1;
    while(k>=0 && !a[k])k--;
    for(int i=k;i>=0;i--)printf("%d",a[i]);
    puts("");
}
void pre(void)
{
    f[3][0] = f[2][0] = 1;
    int tmp[200];
    FOR(i,4,102)
    {
        //puts("**********");
        FOR(j,2,i-1)
        {
            product(f[j],f[i - j + 1],tmp);
            //DEBUG(j);print(f[j]);
            //DEBUG(i-j+1);print(f[i-j+1]);
            //print(tmp);
            int e = 0;
            for(int k=0;k<200;k++)
            {
                int tmp1 = f[i][k] + tmp[k] + e;
                f[i][k] = tmp1%10;
                e = tmp1/10;
            }
        }

    }
}

int main()
{
    //freopen("in","r",stdin);
    pre();
    int n;
    while(~scanf("%d",&n))print(f[n+2]);
    return 0;
}