#include <iostream>
#include <string>
#include <vector>
using namespace std;

unsigned getLength(vector<string>& vps)
{
	unsigned length=1;
	for(unsigned pos=2; pos<vps.size(); ++pos)
	{
		for(length=1; length<=pos; ++length)
			if(vps[pos-length]==vps[pos])
				return length;
	}
	return 0;
}

int main()
{
	string n, vnp, vnq;
	vnp.reserve(100), vnq.reserve(100);   //最长给出的字符串不会超过80个
	vector<int> note;      //用于记录下一次字符串的形态
	vector<string> vps;   //记录每次转换的字符串形态
	
	while(cin>>n, n!="-1")
	{
		vps.clear();
		vnp=n, vnq=vnp;
		int iterations=0, steps=0, length=0;
		while(iterations!=15)
		{
			vnq=vnp;
			note.assign(20, 0);   //记录下次转换的字符串形态
			for(string::size_type i=0; i<vnp.size(); ++i)
			{
				int idx=vnp[i]-'0';
				note[idx]++;
			}
			vnp.clear();
			for(int idx=0; idx<10; ++idx)
			{
				if(note[idx]==0)
					continue;
				if(note[idx]>=10 )
				{
					char c1=note[idx]/10+'0', c2=note[idx]%10+'0';
					vnp.push_back(c1);
					vnp.push_back(c2);
				}
				else
					vnp.push_back(note[idx]+'0');
				vnp.push_back(idx+'0');
			}
			++steps;
			if(vnp==vnq)
				break;
			vps.push_back(vnp);
			if(length=(int)getLength(vps))
				break;
			++iterations;
		}
		if(steps==1)
			cout<<n<<" is self-inventorying"<<endl;
		else if(iterations==15)
			cout<<n<<" can not be classified after 15 iterations"<<endl;
		else if(vnp==vnq)
			cout<<n<<" is self-inventorying after "<<steps-1<<" steps"<<endl;
		else
			cout<<n<<" enters an inventory loop of length "<<length<<endl;
	}
	return 0;
}

• Re:贴下代码 一次ac (1717) 1512335532 2015-07-20 10:26:57