Poj 1016

传送门：http://poj.org/problem?id=1016

数字字符串的压缩，比较

注意指针的使用，注意细节

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

void inventory(char *s,char *d){
    int n[10]={0}; 
    for(int i=0;s[i];i++){
        n[s[i]-'0']++;
    }
    int j=0;
    for(int i=0;i<10;i++){
        if(n[i]){
            if(n[i]<10){
                d[j++]=n[i]+'0';
                d[j++]=i+'0';
            }
            else{
                d[j++]=n[i]/10+'0';
                d[j++]=n[i]%10+'0';
                d[j++]=i+'0';
            }
        }
    }
    d[j]='\0';
    return;
}

int main(){
    char num[20][85];
    while(cin>>num[0]){
        if(!strcmp(num[0],"-1")){//相同为0 
            break;
        }
        for(int k=0;k<17;k++){
            inventory(num[k],num[k+1]);
        } 
        if(!strcmp(num[0],num[1])){
            cout<<num[0]<<" is self-inventorying"<<endl;
            continue;
        }
        bool flag1=false;
        bool flag2=false;
        for(int i=1;i<=15;i++){
            if(!strcmp(num[i],num[i+1])){
                cout<<num[0]<<" is self-inventorying after "<<i<<" steps "<<endl;
                flag1=true;
                break;
            }
        }
        if(!flag1){
            for(int i=14;i>=0;i--){
                if(!strcmp(num[15],num[i])){
                    cout<<num[0]<<" enters an inventory loop of length "<<15-i<<endl;
                    flag2=true;
                    break;
                }
            }
        }
        if(!flag1&&!flag2){
            cout<<num[0]<<" can not be classified after 15 iterations"<<endl;
        }
    }
} 

70,80两个边缘数字，70刚好在15步形成循环，80步在16步形成循环