POJ 1016 Numbers That Count

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<cstdlib>
#include<string>
#include<queue>
#include<vector>
using namespace std;
int main()
{
    char s2[100],s[20][100];
	int i,j,cnt[100],x,y,loop;
	bool flag1;
	while(scanf("%s",s[0]),s[0][0]!='-'){
		flag1=false;
		for(i=0;i<15;i++){
			int len=strlen(s[i]);
			memset(cnt,0,sizeof(cnt));
			for(j=0;j<len;j++)
				cnt[s[i][j]-'0']++;
			for(j=0,x=0;j<10;j++){
				int k=0;
				bool flag=false;
				if(cnt[j])
					flag=true;
				while(cnt[j])
				{
					s2[k++]=cnt[j]%10+'0';
					cnt[j]/=10;
				}
				if(flag){
					for(y=k-1;y>=0;y--)
						s[i+1][x++]=s2[y];
					s[i+1][x++]=j+'0';
				}
			}
			s[i+1][x]='\0';
			if(strcmp(s[i+1],s[i])==0){
				flag1=true;
				break;
			}
			else{
				for(j=0;j<=i;j++)
					if(strcmp(s[j],s[i+1])==0)
						break;
				if(j<=i){
					loop=i-j+1;
					break;
				}
			}
		}
		if(i==15)
			printf("%s can not be classified after 15 iterations\n",s);
		else if(i==0)
			printf("%s is self-inventorying\n",s);
		else if(!flag1)
			printf("%s enters an inventory loop of length %d\n",s,loop);
		else
			printf("%s is self-inventorying after %d steps\n",s,i);
	}
    return 0;
}