北大ACM(POJ1016-Numbers That Count)

Question：http://poj.org/problem?id=1016

问题点：水题。

Memory: 232K        Time: 125MS
Language: C++        Result: Accepted

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

string inventory(string n)
{
    int i;
    int t[10];
    char ch[4];
    memset(t,0,sizeof(t));
    for(i=0;i<n.length();i++)
    {
        t[n.at(i)-'0']++;
    }
    n.clear();
    for(i=0;i<10;i++)
    {
        if(t[i]==0) continue;
        sprintf_s(ch,"%d%d",t[i],i);
        n+=ch;
    }
    return n;
}
int main()
{
    int i,j;
    bool flag;
    string n[16];
    while(cin>>n[0] && n[0]!="-1")
    {
        flag = false;
        for(i=1;i<16;i++)
        {
            n[i] = inventory(n[i-1]);
            for(j=0;j<i;j++)
            {
                if(n[i]==n[j])
                {
                    flag = true;
                    if(i==1)
                    {
                        cout<<n[0]<<" is self-inventorying"<<endl;
                    }
                    else if((i-j)==1)
                    {
                        cout<<n[0]<<" is self-inventorying after "<<j<<" steps"<<endl;
                    }
                    else
                    {
                        cout<<n[0]<<" enters an inventory loop of length "<<i-j<<endl;
                    }
                }
            }
            if(flag) break;
        }
        if(!flag) cout<<n[0]<<" can not be classified after 15 iterations"<<endl;
    }
    return 0;
}