BZOJ 1263 SCOI 2006 整数划分 高精度

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;

struct BigInt{
	int num[10010],len;
	
	BigInt(int _ = 0) {
		memset(num,0,sizeof(num));
		num[len = 1] = _;
	}
	BigInt operator *(int a)const {
		BigInt re;
		re.len = len;
		int temp = 0;
		for(int i = 1; i <= len; ++i) {
			re.num[i] = num[i] * a + temp;
			temp = re.num[i] / 10;
			re.num[i] %= 10;
		}
		while(temp)
			re.num[++re.len] = temp % 10,temp /= 10;
		return re;
	}
};

int n;

int main()
{
	cin >> n;
	BigInt ans(1);
	if(n % 3 == 0)
		for(int i = 1; i <= n / 3; ++i)
			ans = ans * 3;
	else if(n % 3 == 1) {
		for(int i = 1; i <= (n - 1) / 3 - 1; ++i)
			ans = ans * 3;
		ans = ans * 4;
	}
	else {
		for(int i = 1; i <= (n - 1) / 3; ++i)
			ans = ans * 3;
		ans = ans * 2;
	}
	cout << ans.len << endl;
	for(int i = ans.len,T = 1; T <= min(100,ans.len); ++T,--i)
		printf("%d",ans.num[i]);
	return 0;
}