HDU 1023 Train Problem II（ 大数卡特兰 ）

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**链接：****传送门 **

题意：裸卡特兰数，但是必须用大数做

balabala：上交高精度模板题，增加一下熟悉度

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/*************************************************************************
    > File Name: hdu1023.cpp
    > Author:    WArobot 
    > Blog:      http://www.cnblogs.com/WArobot/ 
    > Created Time: 2017年05月11日 星期四 19时25分09秒
 ************************************************************************/

#include<bits/stdc++.h>
using namespace std;

const int maxlen = 10000;
class HP{	public:
	int len , s[maxlen];
	HP(){ (*this) = 0; };
	HP(int inte){ (*this) = inte; };	HP(const char *str){ (*this)=str; };
	friend ostream & operator<<(ostream &cout,const HP &x);
	HP operator = (int inte);		HP operator = (const char*str);
	HP operator * (const HP &b);	HP operator - (const HP &b);
	HP operator / (const HP &b);	int Compare (const HP &b);
	HP operator + (const HP &b);
};
ostream& operator <<(ostream & cout,const HP &x){
	for(int i=x.len ; i>=1 ; i--)	cout<<x.s[i];	return cout;
}
HP HP::operator = (const char *str){
	len = strlen(str);
	for(int i=1;i<=len;i++)	s[i] = str[len-i]-'0';
	return *this;
}
HP HP::operator = (int inte){
	if(inte==0){ len = 1; s[1] = 0; return(*this); };
	for(len = 0;inte>0;){ s[++len]=inte%10; inte/=10; };
	return (*this);
}
HP HP::operator * (const HP &b){
	int i,j;
	HP c;
	c.len = len + b.len;
	for(i=1;i<=c.len;i++)	c.s[i] = 0;
	for(i=1;i<=len;i++) for(j=1;j<=b.len;j++) c.s[i+j-1] += s[i]*b.s[j];
	for(i=1;i<c.len;i++){ c.s[i+1] += c.s[i]/10; c.s[i] %= 10; };
	while(c.s[i]) { c.s[i+1] = c.s[i]/10 ; c.s[i] %= 10 ; i++; }
	while(i>1 && !c.s[i]) i--; c.len = i; 
	return c;
}
HP HP::operator - (const HP &b){
	int i,j;	HP c;
	for(i=1,j=0;i<=len;i++){
		c.s[i] = s[i] - j;	if(i<=b.len) c.s[i] -= b.s[i];
		if(c.s[i]<0){ j=1; c.s[i]+=10; } else j = 0;
	}
	c.len = len;	while(c.len>1 && !c.s[c.len]) c.len--;
	return c;
}
int HP::Compare(const HP &y){
	if(len>y.len)	return 1;
	if(len<y.len)	return -1;
	int i = len;
	while( (i>1)&&( s[i]==y.s[i] ) ) i--;
	return s[i]-y.s[i];
}
HP HP::operator / (const HP &b){
	int i,j;	HP d(0),c;
	for(i=len;i>0;i--){
		if( !(d.len==1 && d.s[1]==0) )
			{ for( j = d.len; j>0;j--) d.s[j+1] = d.s[j]; ++d.len; }
		d.s[1] = s[i];	c.s[i] = 0;
		while( (j=d.Compare(b))>=0 )
			{ d = d-b; c.s[i]++; if(j==0) break; }
	}
	c.len = len;	while( (c.len>1)&&(c.s[c.len]==0) )	c.len--;
	return c;
}
HP HP::operator + (const HP &b){
	int i;	HP c;	c.s[1] = 0;
	for(i = 1; i<=len || i<=b.len || c.s[i]; i++ ){
		if( i<=len ) c.s[i] += s[i];
		if( i<=b.len ) c.s[i] += b.s[i];
		c.s[i+1] = c.s[i]/10;	c.s[i] %= 10;
	}
	c.len = i-1;	if( c.len == 0 )	c.len = 1;
	return c;
}
int main(){
	HP h[102];
	h[0] = h[1] = 1;
	for(int i=2;i<=100;i++){
		for(int j=0;j<i;j++){
			h[i] = h[i] + (h[j]*h[i-1-j]);
		}
	}
	int n;
	while(~scanf("%d",&n)){
		cout<<h[n]<<endl;
	}
	return 0;
}