HDU 1333 基础数论 暴力

定义一种数位simth数，该数的各位之和等于其所有质因子所有位数字之和，现给出n求大于n的最小该种数，n最大不超过8位，那么直接暴力就可以了。

/** @Date    : 2017-09-08 14:12:08
  * @FileName: HDU 1333 素因子 暴力.cpp
  * @Platform: Windows
  * @Author  : Lweleth (SoungEarlf@gmail.com)
  * @Link    : https://github.com/
  * @Version : $Id$
  */
#include <bits/stdc++.h>
#define LL long long
#define PII pair<int ,int>
#define MP(x, y) make_pair((x),(y))
#define fi first
#define se second
#define PB(x) push_back((x))
#define MMG(x) memset((x), -1,sizeof(x))
#define MMF(x) memset((x),0,sizeof(x))
#define MMI(x) memset((x), INF, sizeof(x))
using namespace std;

const int INF = 0x3f3f3f3f;
const int N = 1e5+20;
const double eps = 1e-8;

LL pri[N];
LL sum[N];
bool vis[N];
int c = 0;
void prime()
{
	MMF(vis);
	MMF(sum);
	for(int i = 2; i < N; i++)
	{
		if(!vis[i])
		{
			pri[c++] = i;
			LL t = i;
			while(t)
				sum[c - 1] += t % 10, t /= 10;
		}
		for(int j = 0; j < c && i * pri[j] < N; j++)
		{
			vis[i * pri[j]] = 1;
			if(i % pri[j] == 0) break;
		}
	}
}

int main()
{
	prime();
	LL n;
	while(cin >> n && n)
	{
		for(int i = n + 1; ;i++)
		{
			LL tmp = i;
			LL a = 0;
			while(tmp)
				a += tmp % 10, tmp /= 10;

			LL b = 0;
			LL t = i;
			for(int j = 0; j < c && pri[j] * pri[j] <= t; j++)
			{
				if(t % pri[j] == 0)
				{
					while(t % pri[j] == 0)
						t /= pri[j], b+=sum[j];
				}
			}
			if(t != i && t > 1) 
				while(t)
					b += t % 10, t/= 10;
			if(b == a)
			{
				printf("%lld
", i);
				break;
			}
		}
	}
    return 0;
}